Progressive Bank Acquisition . On July 7, 2025, Business First executed a definitive agreement to acquire Progressive Bancorp, Inc. (“Progressive”) and its wholly-owned bank subsidiary, Progressive Bank. As of March 31, 2025, Progressive reported total assets of $752 million, deposits of $673 million, and equity of $65 million.

Stable Net Interest Margin (NIM). Net interest income totaled $67.0 million and net interest margin and net interest spread were 3.68% and 2.88%, respectively, compared to $66.0 million, 3.68% and 2.91% for the linked quarter. Non-GAAP net interest margin and net interest spread (excluding loan discount accretion of $0.8 million) were 3.64% and 2.84% for the quarter ended June 30, 2025, compared to 3.64% and 2.86% (excluding loan discount accretion of $0.8 million) for the linked quarter. Net interest margin for the quarter was impacted by excess funding utilized during the core conversion (~3 basis points, “bps”) and incremental funding cost associated with replacing the Kaplan deposit portfolio (~2 bps).

Core Conversion . Business First successfully converted its core processing for loans, deposits, and the general ledger to Fidelity Information Systems (“FIS”) to improve capabilities and efficiencies for future growth.

Branch Optimization. In early April, Business First sold a banking branch located in Kaplan, LA (Kaplan) resulting in a net capital injection of $3.4 million. The transaction included a sale of $50.7 million of deposits for an 8.0% purchase premium. The sale is estimated to result in $750,000 lower annual operating cost.

Capital Growth. Common equity to total assets increased from 9.69% to 9.77% and tangible common equity to tangible assets increased from 8.06% to 8.19%, 1.61% or 6.47% annualized, compared to the linked quarter, driven largely by solid quarterly earnings. On a non-GAAP basis, tangible book value per common share increased to $28.61 as of June 30, 2025, a 77 basis point increase, 3.70% or 14.82% annualized, compared to the linked quarter.

Sustained Core Performance. Return to common shareholders on average assets, on an annualized basis, was 1.07% for the quarter ended June 30, 2025, or 1.01% on a non-GAAP basis, compared to 1.00% or 1.01% on a non-GAAP basis for the linked quarter.

On Thursday, July 24, 2025, Business First’s board of directors declared a quarterly preferred dividend in the amount of $18.75 per share, which is the full quarterly dividend of 1.875% based on the per annum rate of 7.50%. Additionally, the board of directors declared a quarterly common dividend based upon financial performance for the second quarter in the amount of $0.14 per share of common stock. The preferred and common dividends will be paid on August 31, 2025, or as soon thereafter as practicable, to the shareholders of record as of August 15, 2025.

“Between our latest partnership announcement, successful core conversion and legacy branch repositioning, this was a quarter that positions us for continued growth and development in the coming quarters and years,” said Jude Melville, chairman, president and CEO of Business First Bancshares, “I’m especially proud that our team conducted these productive operational activities while continuing to post consistent earnings and healthy balance sheet growth including our tangible book value and capital levels. We look forward to converting our Oakwood franchise systems late in the third quarter and competing from a position of strength in the Dallas market as a fully integrated team.”

BATON ROUGE, La., July 28, 2025 (GLOBE NEWSWIRE) — Business First Bancshares, Inc. (NASDAQ: BFST) (Business First), parent company of b1BANK, today announced its unaudited results for the quarter ended June 30, 2025. Business First reported net income available to common shareholders of $20.8 million or $0.70 per diluted common share, increases of $1.6 million and $0.05, respectively, compared to the linked quarter ended March 31, 2025. On a non-GAAP basis, core net income for the quarter ended June 30, 2025, which excludes certain income and expenses, was $19.5 million or $0.66 per diluted common share, an increase of $0.2 million and $0.01, from the linked quarter.

Story continues

Statement of Financial Condition

Loans

Loans held for investment increased $66.7 million or 1.12%, 4.48% annualized. The commercial and commercial real estates portfolios increased $98.8 million and $61.6 million, respectively, compared to the linked quarter. The construction portfolio declined $33.4 million, or 5.27% compared to the linked quarter. Texas-based loans represented approximately 40% of the overall loan portfolio as of June 30, 2025, based on unpaid principal balance.

Credit Quality

Credit quality metrics migrated upwards compared to the linked quarter. The ratio of nonperforming loans compared to loans held for investment increased 28 bps to 0.97% at June 30, 2025, while the ratio of nonperforming assets compared to total assets increased 21 bps to 0.76% compared to the linked quarter. The commercial real estate, commercial, and residential real estate portfolios encompass approximately $22.5 million, $20.8 million, and $7.5 million, respectively, of the $56.4 million nonaccrual balance at June 30, 2025.

Securities

The securities portfolio increased $5.9 million, or 0.64%, from the linked quarter, impacted by $6.4 million in positive fair value adjustments. The securities portfolio, based on estimated fair value, represented 11.83% of total assets as of June 30, 2025.

Deposits

Deposits decreased $38.5 million or 0.60%, 2.39% annualized, for the quarter ended June 30, 2025, compared to the linked quarter. Excluding the $50.7 million in deposits transferred in the Kaplan sale, deposits increased $12.1 million or 0.19%, 0.76% annualized.

Noninterest bearing deposits increased $102.4 million or 7.83% and interest-bearing deposits decreased $140.9 million or 10.77%. The portfolio was impacted by various transactions during the quarter. The money market portfolio was affected by approximately $62.8 million of withdrawals from financial institutional accounts with a weighted average rate of 4.45%. These withdrawals were replaced with more efficient brokered certificates of deposits (CDs). The Kaplan sale accounted for reductions of approximately $41.5 million in interest bearing deposits and $9.2 million in noninterest bearing deposits. Some of the migration was mitigated through successful retail CD promotion offers which generated $43.0 million increase in the portfolio. Additionally, the noninterest bearing portfolio benefited from a short-term inflow of approximately $60 million in deposits which subsequently were withdrawn after quarter end.

Borrowings

Borrowings increased $179.0 million or 41.25%, from the linked quarter due primarily to an increase in short-term Federal Home Loan Bank advances. Additional liquidity was utilized during the quarter as Business First’s main correspondent banking relationship was changed during the core conversion process, as well as borrowings for short-term deposit fluctuations.

Shareholders’ Equity

Shareholders’ equity increased $22.1 million or 2.68% during the quarter ended June 30, 2025. Accumulated other comprehensive income (AOCI) increased $5.1 million or 9.61%, during the quarter due to positive after-tax fair value adjustments in the securities portfolio. Book value per common share increased to $26.23 at June 30, 2025, compared to $25.51 at March 31, 2025, due to strong earnings and positive fair value adjustments. On a non-GAAP basis, tangible book value per common share increased from $20.84 at the linked quarter to $21.61 at June 30, 2025, 3.70% or 14.82% annualized.

Results of Operations

Net Interest Income

For the quarter ended June 30, 2025, net interest income totaled $67.0 million, compared to $66.0 million from the linked quarter. Loan and interest-earning asset yields of 6.96% and 6.31%, decreased 3 and 4 bps, respectively, compared to 6.99% and 6.35% from the linked quarter. Net interest margin and net interest spread were 3.68% and 2.88% compared to 3.68% and 2.91% for the linked quarter. The overall cost of funds, which included noninterest-bearing deposits, declined 4 bps from 2.82% to 2.78% for the quarter ended June 30, 2025, despite the sale of $50.7 million in deposits associated with the Kaplan, LA banking branch sale in April (~2 bps reduction in margin). Additionally, margin was also negatively impacted by ~3 bps due to excess cash carried during the transfer of our primary correspondent banking relationship through the core conversion process.

Non-GAAP net interest income (excluding loan discount accretion of $0.8 million) totaled $66.3 million for the quarter ended June 30, 2025, compared to $65.2 million (excluding loan discount accretion of $0.8 million) for the linked quarter. Non-GAAP net interest margin and net interest spread (excluding loan discount accretion of $0.8 million) were 3.64% and 2.84%, respectively, for the quarter ended June 30, 2025, compared to 3.64% and 2.86% (excluding loan discount accretion of $0.8 million) for the linked quarter.

Provision for Credit Losses

During the quarter ended June 30, 2025, Business First recorded a provision for credit losses of $2.2 million, compared to $2.8 million from the linked quarter. The current quarter’s reserve was largely impacted by an additional $1.6 million reserve on a loan transferred to nonaccrual status. At June 30, 2025, the ratio of allowance for credit losses to loans held for investment ratio was 1.02%, compared to 1.01% the linked quarter.

Other Income

For the quarter ended June 30, 2025, other income increased $1.2 million or 8.99%, compared to the linked quarter. The net increase was largely attributable to a $3.4 million gain on the Kaplan sale, offset largely by a $1.0 million reduction in equity investment income, and a $475,000 reduction in gain on sale of Small Business Administration (SBA) loans.

Other Expenses

For the quarter ended June 30, 2025, other expenses increased $628,000 or 1.24%, compared to the linked quarter. The increase was largely attributable to a $2.1 million increase in data processing expenses, of which $1.0 million was associated with core conversion expenses, offset by a $1.2 million reduction in salaries and benefits largely due to lower incentive-based expenses.

Return on Assets and Common Equity

Return to common shareholders on average assets and common equity, each on an annualized basis, were 1.07% and 10.87% for the quarter ended June 30, 2025, compared to 1.00% and 10.48%, respectively, for the linked quarter. Non-GAAP return to common shareholders on average assets and common equity, each on an annualized basis, were 1.01% and 10.23% for the quarter ended June 30, 2025, compared to 1.01% and 10.53%, for the linked quarter.

Conference Call and Webcast

Executive management will host a conference call and webcast to discuss results on Monday, July 28, 2025, at 9:00 a.m. Central Time. Interested parties may attend the call by dialing toll-free 1-800-715-9871 (North America only), conference ID 2799880, or asking for the Business First Bancshares conference call. The live webcast can be found at https://edge.media-server.com/mmc/p/jqbmtwns. On the day of the presentation, the corresponding slide presentation will be available to view on the b1BANK website at https://www.b1bank.com/shareholder-info.

About Business First Bancshares, Inc.

Business First Bancshares, Inc., (Nasdaq: BFST) through its banking subsidiary b1BANK, has $7.9 billion in assets, $5.4 billion in assets under management through b1BANK’s affiliate Smith Shellnut Wilson, LLC (SSW) (excludes $0.9 billion of b1BANK assets managed by SSW) and operates Banking Centers and Loan Production Offices in markets across Louisiana and Texas providing commercial and personal banking products and services. b1BANK is a 2024 Mastercard “Innovation Award” winner and multiyear winner of American Banker Magazine’s “Best Banks to Work For.” Visit b1BANK.com for more information.

Non-GAAP Financial Measures

This press release includes certain non-GAAP financial measures (e.g., referenced as “core” or “tangible”) intended to supplement, not substitute for, comparable GAAP measures. “Core” measures typically adjust income available to common shareholders for certain significant activities or transactions that, in management’s opinion, can distort period-to-period comparisons of Business First’s performance. Transactions that are typically excluded from non-GAAP “core” measures include realized and unrealized gains/losses on former bank premises and equipment, investment sales, acquisition-related expenses (including, but not limited to, legal costs, system conversion costs, severance and retention payments, etc.). “Tangible” measures adjust common equity by subtracting goodwill, core deposit intangibles, and customer intangibles, net of accumulated amortization. Management believes presentations of these non-GAAP financial measures provide useful supplemental information that is essential to a proper understanding of the operating results of Business First’s core business. These non-GAAP disclosures are not necessarily comparable to non-GAAP measures that may be presented by other companies. Reconciliations of non-GAAP financial measures to GAAP financial measures are provided at the end of the tables below.

Special Note Regarding Forward-Looking Statements

Certain statements contained in this release may not be based on historical facts and are “forward-looking statements” within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. These forward-looking statements may be identified by their reference to a future period or periods or by the use of forward-looking terminology such as “anticipate,” “believe,” “estimate,” “expect,” “may,” “might,” “will,” “would,” “could,” or “intend.” We caution you not to place undue reliance on the forward-looking statements contained in this news release, in that actual results could differ materially from those indicated in such forward-looking statements as a result of a variety of factors, including those factors specified in our Annual Report on Form 10-K and other public filings. We undertake no obligation to update these forward-looking statements to reflect events or circumstances that occur after the date of this news release.

Additional Information

For additional information about Business First, you may obtain Business First’s reports that are filed with the Securities and Exchange Commission (SEC) free of charge by using the SEC’s EDGAR service on the SEC’s website at www.SEC.gov or by contacting the SEC for further information at 1-800-SEC-0330. Alternatively, these documents can be obtained free of charge from Business First by directing a request to: Business First Bancshares, Inc., 500 Laurel Street, Suite 101, Baton Rouge, Louisiana 70801, Attention: Corporate Secretary.

No Offer or Solicitation

This release does not constitute or form part of any offer to sell, or a solicitation of an offer to purchase, any securities of Business First. There will be no sale of securities in any jurisdiction in which such an offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of such jurisdiction.

Additional Information and Where to Find It

This communication is being made with respect to the proposed transaction involving Business First and Progressive. This material is not a solicitation of any vote or approval of the Progressive shareholders and is not a substitute for the proxy statement/prospectus or any other documents that Business First and Progressive may send to their respective shareholders in connection with the proposed transaction. This communication does not constitute an offer to sell or the solicitation of an offer to buy any securities.

In connection with the proposed transaction, Business First will file with the SEC a Registration Statement on Form S-4 (the “Registration Statement”) that will include a proxy statement of Progressive and a prospectus of Business First, as well as other relevant documents concerning the proposed transaction. Before making any voting or investment decision, investors and shareholders are urged to read carefully the Registration Statement and the proxy statement/prospectus regarding the proposed transaction, as well as any other relevant documents filed with the SEC and any amendments or supplements to those documents, because they will contain important information. Progressive will mail the proxy statement/prospectus to its shareholders. Shareholders are also urged to carefully review and consider Business First’s public filings with the SEC, including, but not limited to, its proxy statements, its Annual Report on Form 10-K, its Quarterly Reports on Form 10-Q and its Current Reports on Form 8-K. Copies of the Registration Statement and proxy statement/prospectus and other filings incorporated by reference therein, as well as other filings containing information about Business First, may be obtained, free of charge, as they become available at the SEC’s website at www.sec.gov. You will also be able to obtain these documents when they are filed, free of charge, from Business First at www.b1BANK.com. Copies of the proxy statement/prospectus can also be obtained, when they become available, free of charge, by directing a request to Business First Bancshares, Inc., 500 Laurel Street, Suite 101, Baton Rouge, LA 70801, Attention: Corporate Secretary, Telephone: 225-248-7600.

Participants in the Solicitation

Business First, Progressive and certain of their respective directors, executive officers and employees may, under the SEC’s rules, be deemed to be participants in the solicitation of proxies of Progressive’s shareholders in connection with the proposed transaction. Information about Business First’s directors and executive officers is available in its definitive proxy statement relating to its 2025 annual meeting of shareholders, which was filed with the SEC on April 9, 2025, and other documents filed by Business First with the SEC. Other information regarding the persons who may, under the SEC’s rules, be deemed to be participants in the solicitation of proxies of Progressive’s shareholders in connection with the proposed transaction, and a description of their direct and indirect interests, by holdings or otherwise, will be contained in the proxy statement/prospectus regarding the proposed transaction and other relevant materials to be filed with the SEC when they become available. Free copies of these documents may be obtained as described in the preceding paragraph.

Investor Relations Contact:

Gregory Robertson Matt Sealy 337.721.2701 225.388.6116 Gregory.Robertson@b1bank.com Matt.Sealy@b1bank.com

Media Contact:

Misty Albrecht b1BANK 225.286.7879 Misty.Albrecht@b1BANK.com

Business First Bancshares, Inc. Selected Financial Information (Unaudited) Three Months Ended (Dollars in thousands) June 30,

2025 March 31,

2025 June 30,

2024 Balance Sheet Ratios Loans (HFI) to Deposits 94.21 % 92.61 % 97.80 % Shareholders’ Equity to Assets Ratio 10.67 % 10.61 % 9.91 % Loans Receivable Held for Investment (HFI) Commercial $ 1,960,974 $ 1,862,176 $ 1,520,392 Real Estate: Commercial 2,533,761 2,472,121 2,198,119 Construction 600,292 633,698 637,466 Residential 879,891 934,357 743,876 Total Real Estate 4,013,944 4,040,176 3,579,461 Consumer and Other 72,732 78,567 62,999 Total Loans (Held for Investment) $ 6,047,650 $ 5,980,919 $ 5,162,852 Allowance for Loan Losses Balance, Beginning of Period $ 56,863 $ 54,840 $ 41,165 Oakwood – PCD ALLL — — — Charge-Offs – Quarterly (921 ) (1,648 ) (1,426 ) Recoveries – Quarterly 99 671 91 Provision for Loan Losses – Quarterly 2,455 3,000 1,582 Balance, End of Period $ 58,496 $ 56,863 $ 41,412 Allowance for Loan Losses to Total Loans (HFI) 0.97 % 0.95 % 0.80 % Allowance for Credit Losses to Total Loans (HFI)/(1) 1.02 % 1.01 % 0.86 % Net Charge-Offs (Recoveries) to Average Quarterly Total Loans 0.01 % 0.02 % 0.03 % Remaining Loan Purchase Discount $ 10,099 $ 11,322 $ 9,690 Nonperforming Assets Nonperforming Nonaccrual Loans $ 56,377 $ 35,915 $ 21,008 Loans Past Due 90 Days or More 2,467 5,635 1,355 Total Nonperforming Loans 58,844 41,550 22,363 Other Nonperforming Assets: Other Real Estate Owned 1,473 1,282 1,983 Other Nonperforming Assets — — — Total other Nonperforming Assets 1,473 1,282 1,983 Total Nonperforming Assets $ 60,317 $ 42,832 $ 24,346 Nonperforming Loans to Total Loans (HFI) 0.97 % 0.69 % 0.43 % Nonperforming Assets to Total Assets 0.76 % 0.55 % 0.36 % (1) Allowance for Credit Losses includes the Allowance for Loan Loss and Reserve for Unfunded Commitments.

Business First Bancshares, Inc. Selected Financial Information (Unaudited) Three Months Ended Six Months Ended (Dollars in thousands, except per share data) June 30,

2025 March 31,

2025 June 30,

2024 June 30,

2025 June 30,

2024 Per Share Data Basic Earnings per Common Share $ 0.70 $ 0.65 $ 0.63 $ 1.36 $ 1.11 Diluted Earnings per Common Share 0.70 0.65 0.62 1.35 1.10 Dividends per Common Share 0.14 0.14 0.14 0.28 0.28 Book Value per Common Share 26.23 25.51 23.24 26.23 23.24 Average Common Shares Outstanding 29,517,495 29,329,668 25,265,495 29,354,228 25,196,079 Average Diluted Common Shares Outstanding 29,586,975 29,545,921 25,395,614 29,500,061 25,412,142 End of Period Common Shares Outstanding 29,602,970 29,572,297 25,502,175 29,602,970 25,502,175 Annualized Performance Ratios Return to Common Shareholders on Average Assets (1) 1.07 % 1.00 % 0.95 % 1.04 % 0.84 % Return to Common Shareholders on Average Common Equity (1) 10.87 % 10.48 % 10.94 % 10.68 % 9.73 % Net Interest Margin (1) 3.68 % 3.68 % 3.45 % 3.68 % 3.39 % Net Interest Spread (1) 2.88 % 2.91 % 2.47 % 2.90 % 2.42 % Efficiency Ratio (2) 62.83 % 63.85 % 65.14 % 63.33 % 67.37 % Total Quarterly/Year-to-Date Average Assets $ 7,791,372 $ 7,750,982 $ 6,711,173 $ 7,771,289 $ 6,689,350 Total Quarterly/Year-to-Date Average Common Equity 765,884 742,930 583,184 754,470 580,414 Other Expenses Salaries and Employee Benefits

$ 28,317 $ 29,497 $ 25,523 $ 57,814 $ 50,939 Occupancy and Bank Premises 3,119 3,401 2,634 6,520 5,148 Depreciation and Amortization 2,076 2,152 1,742 4,228 3,418 Data Processing 5,321 3,236 2,641 8,557 5,220 FDIC Assessment Fees 861 1,184 874 2,045 1,702 Legal and Other Professional Fees 1,093 1,013 1,042 2,106 1,908 Advertising and Promotions 1,088 1,291 966 2,379 2,111 Utilities and Communications 743 733 718 1,476 1,392 Ad Valorem Shares Tax 1,125 1,125 900 2,250 1,800 Directors’ Fees 193 279 268 472 550 Other Real Estate Owned Expenses and Write-Downs 27 23 71 50 108 Merger and Conversion-Related Expenses 210 250 409 460 749 Other 7,033 6,394 5,322 13,427 10,587 Total Other Expenses $ 51,206 $ 50,578 $ 43,110 $ 101,784 $ 85,632 Other Income Service Charges on Deposit Accounts $ 2,633 $ 2,860 $ 2,537 $ 5,493 $ 4,976 Gain (Loss) on Sales of Securities (47 ) (1 ) — (48 ) (1 ) Debit Card and ATM Fee Income 1,958 1,858 1,950 3,816 3,726 Bank-Owned Life Insurance Income 758 808 627 1,566 1,206 Gain on Sales of Loans 781 1,256 2,460 2,037 2,599 Mortgage Origination Income 55 110 35 165 104 Fees and Brokerage Commission 1,980 2,148 1,875 4,128 3,812 Gain (Loss) on Sales of Other Real Estate Owned 56 (268 ) 2 (212 ) 65 Gain (Loss) on Disposal of Other Assets — 155 (15 ) 155 (15 ) Gain on Extinguishment of Debt — 630 — 630 — Gain on Branch Sale 3,360 — — 3,360 — Swap Fee Income 808 739 285 1,547 514 Pass-Through Income (Loss) from Other Investments (246 ) 751 392 505 686 Other 2,319 2,180 2,028 4,499 3,890 Total Other Income $ 14,415 $ 13,226 $ 12,176 $ 27,641 $ 21,562 (1) Average outstanding balances are determined utilizing daily averages and average yield/rate is calculated utilizing an actual day count convention. (2) Noninterest expense (excluding provision for loan losses) divided by noninterest income (excluding security sales gains/losses) plus net interest income less gain/loss on sales of securities.

Business First Bancshares, Inc. Consolidated Balance Sheets (Unaudited) (Dollars in thousands) June 30,

2025 March 31,

2025 June 30,

2024 Assets Cash and Due From Banks $ 495,757 $ 312,887 $ 208,051 Federal Funds Sold 39,296 117,422 113,587 Securities Purchased under Agreements to Resell 25,433 50,589 — Securities Available for Sale, at Fair Values 926,450 920,573 875,048 Mortgage Loans Held for Sale 677 — 680 Loans and Lease Receivable 6,047,650 5,980,919 5,162,852 Allowance for Loan Losses (58,496 ) (56,863 ) (41,412 ) Net Loans and Lease Receivable 5,989,154 5,924,056 5,121,440 Premises and Equipment, Net 79,007 81,582 68,545 Accrued Interest Receivable 36,738 33,741 30,617 Other Equity Securities 48,736 40,947 38,805 Other Real Estate Owned 1,473 1,282 1,983 Cash Value of Life Insurance 118,707 117,950 100,684 Deferred Taxes, Net 25,222 25,289 25,888 Goodwill 121,146 121,691 91,527 Core Deposit and Customer Intangibles 15,775 16,538 10,849 Other Assets 24,723 20,181 16,185 Total Assets $ 7,948,294 $ 7,784,728 $ 6,703,889 Liabilities Deposits Noninterest-Bearing $ 1,410,708 $ 1,308,312 $ 1,310,204 Interest-Bearing 5,008,943 5,149,869 4,253,466 Total Deposits 6,419,651 6,458,181 5,563,670 Securities Sold Under Agreements to Repurchase 22,557 19,046 18,445 Federal Home Loan Bank Borrowings 492,946 317,352 305,208 Subordinated Debt 92,645 92,702 99,875 Subordinated Debt – Trust Preferred Securities 5,000 5,000 5,000 Accrued Interest Payable 4,829 5,356 4,517 Other Liabilities 62,226 60,779 42,644 Total Liabilities 7,099,854 6,958,416 6,039,359 Shareholders’ Equity Preferred Stock 71,930 71,930 71,930 Common Stock 29,603 29,572 25,502 Additional Paid-In Capital 502,046 501,609 397,851 Retained Earnings 292,629 276,045 237,031 Accumulated Other Comprehensive Loss (47,768 ) (52,844 ) (67,784 ) Total Shareholders’ Equity 848,440 826,312 664,530 Total Liabilities and Shareholders’ Equity $ 7,948,294 $ 7,784,728 $ 6,703,889

Business First Bancshares, Inc. Consolidated Statements of Income (Unaudited) Three Months Ended Six Months Ended (Dollars in thousands) June 30,

2025 March 31,

2025 June 30,

2024 June 30,

2025 June 30,

2024 Interest Income: Interest and Fees on Loans $ 104,028 $ 102,992 $ 90,604 $ 207,020 $ 176,551 Interest and Dividends on Securities 6,906 6,614 5,933 13,520 11,532 Interest on Federal Funds Sold and Due From Banks 3,916 4,088 3,333 8,003 7,798 Total Interest Income 114,850 113,693 99,870 228,543 195,881 — Interest Expense: — Interest on Deposits 41,546 42,439 40,900 83,985 78,929 Interest on Borrowings 6,262 5,271 4,961 11,533 11,412 Total Interest Expense 47,808 47,710 45,861 95,518 90,341 — Net Interest Income 67,042 65,983 54,009 133,025 105,540 — Provision for Credit Losses 2,225 2,812 1,310 5,037 2,496 — Net Interest Income After Provision for Credit Losses 64,817 63,171 52,699 127,988 103,044 — Other Income: — Service Charges on Deposit Accounts 2,633 2,860 2,537 5,493 4,976 (Loss) Gain on Sales of Securities (47 ) (1 ) — (48 ) (1 ) Gain on Sales of Loans 781 1,256 2,460 2,037 2,599 Other Income 11,048 9,111 7,179 20,159 13,988 Total Other Income 14,415 13,226 12,176 27,641 21,562 — Other Expenses: — Salaries and Employee Benefits 28,317 29,497 25,523 57,814 50,939 Occupancy and Equipment Expense 7,162 7,356 5,717 14,518 11,074 Merger and Conversion-Related Expense 210 250 409 460 749 Other Expenses 15,517 13,475 11,461 28,992 22,870 Total Other Expenses 51,206 50,578 43,110 101,784 85,632 — Income Before Income Taxes 28,026 25,819 21,765 53,845 38,974 — Provision for Income Taxes 5,923 5,276 4,559 11,199 8,198 — Net Income 22,103 20,543 17,206 42,646 30,776 — Preferred Stock Dividends 1,350 1,350 1,350 2,700 2,700 $ — Net Income Available to Common Shareholders $ 20,753 $ 19,193 $ 15,856 $ 39,946 $ 28,076

Business First Bancshares, Inc. Consolidated Net Interest Margin (Unaudited) Three Months Ended June 30, 2025 March 31, 2025 June 30, 2024 (Dollars in thousands) Average Outstanding Balance Interest Earned/Interest Paid Average Yield/Rate Average Outstanding Balance Interest Earned/Interest Paid Average Yield/Rate Average Outstanding Balance Interest Earned/Interest Paid Average Yield/Rate Assets Interest Earning Assets: Total Loans $ 5,995,490 $ 104,028 6.96 % $ 5,972,120 $ 102,992 6.99 % $ 5,153,642 $ 90,604 7.07 % Securities 937,099 6,906 2.96 % 924,693 6,614 2.90 % 891,384 5,933 2.68 % Securities Purchased under Agreements to Resell 31,172 401 5.16 % 50,836 651 5.19 % — — — % Interest-Bearing Deposit in Other Banks 336,138 3,515 4.19 % 315,750 3,436 4.41 % 246,590 3,333 5.44 % Total Interest Earning Assets 7,299,899 114,850 6.31 % 7,263,399 113,693 6.35 % 6,291,616 99,870 6.38 % Allowance for Loan Losses (56,934 ) . (54,711 ) . (41,450 ) Noninterest- Earning Assets 548,406 542,294 461,007 Total Assets $ 7,791,371 $ 114,850 $ 7,750,982 $ 113,693 $ 6,711,173 $ 99,870 Liabilities and Shareholders’ Equity Interest-Bearing Liabilities: Interest-Bearing Deposits Subordinated Debt 5,029,981 41,546 3.31 % 5,141,498 42,439 3.35 % 4,268,207 40,900 3.85 % Subordinated Debt – Trust Preferred Securities 92,682 1,235 5.34 % 97,251 1,262 5.26 % 99,913 1,354 5.45 % Bank Term Funding Program 5,000 100 8.02 % 5,000 99 8.03 % 5,000 113 9.09 % Advances from Federal Home Loan Bank (FHLB) 447,271 4,793 4.30 % 362,092 3,796 4.25 % 324,691 3,372 4.18 % Other Borrowings 20,514 134 2.62 % 18,321 114 2.52 % 19,164 122 2.56 % Total Interest-Bearing Liabilities $ 5,595,448 $ 47,808 3.43 % $ 5,624,162 $ 47,710 3.44 % $ 4,716,975 $ 45,861 3.91 % Noninterest-Bearing Liabilities: Noninterest-Bearing Deposits $ 1,292,262 $ 1,244,793 $ 1,297,085 Other Liabilities 65,847 67,167 41,999 Total Noninterest-Bearing Liabilities 1,358,109 1,311,960 1,339,084 Shareholders’ Equity: Common Shareholders’ Equity 765,884 742,930 583,184 Preferred Equity 71,930 71,930 71,930 Total Shareholders’ Equity 837,814 814,860 655,114 Total Liabilities and Shareholders’ Equity $ 7,791,371 $ 7,750,982 $ 6,711,173 Net Interest Spread 2.88 % 2.91 % 2.47 % Net Interest Income $ 67,042 $ 65,983 $ 54,009 Net Interest Margin 3.68 % 3.68 % 3.45 % Overall Cost of Funds 2.78 % 2.82 % 3.07 % Note: Average outstanding balances are determined utilizing daily averages and an actual day count convention.

Business First Bancshares, Inc. Consolidated Net Interest Margin (Unaudited) Six Months Ended (Dollars in thousands) June 30, 2025 June 30, 2024 Average

Outstanding

Balance Interest

Earned/Interest

Paid Average

Yield/Rate Average

Outstanding

Balance Interest

Earned/Interest

Paid Average

Yield/Rate Assets Interest Earning Assets: Total Loans $ 5,983,870 $ 207,020 6.98 % $ 5,090,289 $ 176,551 6.97 % Securities 930,930 13,520 2.93 % 890,158 11,532 2.61 % Securities Purchased under Agreements to Resell

40,950 1,052 5.18 % Interest-Bearing Deposit in Other Banks 326,000 6,951 4.30 % 288,426 7,798 5.44 % Total Interest Earning Assets 7,281,750 228,543 6.33 % 6,268,873 195,881 6.28 % Allowance for Loan Losses (55,829 ) (40,988 ) Noninterest- Earning Assets 545,367 461,465 Total Assets $ 7,771,288 $ 228,543 $ 6,689,350 $ 195,881 Liabilities and Shareholders’ Equity Interest-Bearing Liabilities: Interest-Bearing Deposits $ 5,085,431 $ 83,985 3.33 % $ 4,170,406 $ 78,929 3.81 % Subordinated Debt 94,954 2,497 5.30 % 99,942 2,710 5.45 % Subordinated Debt – Trust Preferred Securities 5,000 199 8.03 % 5,000 226 9.09 % Bank Term Funding Program

— — — % 130,220 2,788 4.31 % Advances from Federal Home Loan Bank (FHLB) 404,917 8,589 4.28 % 274,096 5,466 4.01 % Other Borrowings 19,424 248 2.57 % 17,640 222 2.53 % Total Interest-Bearing Liabilities $ 5,609,726 $ 95,518 3.43 % $ 4,697,304 $ 90,341 3.87 % Noninterest-Bearing Liabilities: Noninterest-Bearing Deposits $ 1,268,659 $ 1,289,948 Other Liabilities 66,503 49,754 Total Noninterest-Bearing Liabilities 1,335,162 1,339,702 Shareholders’ Equity: Common Shareholders’ Equity 754,470 580,414 Preferred Equity 71,930 71,930 Total Shareholders’ Equity 826,400 652,344 Total Liabilities and Shareholders’ Equity $ 7,771,288 $ 6,689,350 Net Interest Spread 2.90 % 2.42 % Net Interest Income $ 133,025 $ 105,540 Net Interest Margin 3.68 % 3.39 % Overall Cost of Funds 2.80 % 3.03 % Note: Average outstanding balances are determined utilizing daily averages and an actual day count convention.

Business First Bancshares, Inc. Non-GAAP Measures (Unaudited) Three Months Ended Six Months Ended (Dollars in thousands, except per share data) June 30,

2025 March 31,

2025 June 30,

2024 June 30,

2025 June 30,

2024 Interest Income: Interest income $ 114,850 $ 113,693 $ 99,870 $ 228,543 $ 195,881 Core interest income 114,850 113,693 98,870 228,543 195,881 Interest Expense: Interest expense 47,808 47,710 45,861 95,518 90,341 Core interest expense 47,808 47,710 45,861 95,518 90,341 Provision for Credit Losses: (b) Provision for credit losses 2,225 2,812 1,310 5,037 2,496 Core provision expense 2,225 2,812 1,310 5,037 2,496 Other Income: Other income 14,415 13,226 12,176 27,641 21,562 Gain on former bank premises and equipment — (155 ) — (155 ) (50 ) Loss (Gain) on sale of securities 47 1 — 48 1 Gain on extinguishment of debt — (630 ) — (630 ) — Gain on branch sale

(3,360 ) — — (3,360 ) Core other income 11,102 12,442 12,176 23,544 21,513 Other Expense: Other expense 51,206 50,578 43,110 101,784 85,632 Acquisition-related expenses (2) (570 ) (679 ) (419 ) (1,249 ) (1,134 ) Core conversion expenses (1,008 ) (216 ) — (1,224 ) — Core other expense 49,628 49,683 42,691 99,311 84,498 Pre-Tax Income: (a) Pre-tax income 28,026 25,819 21,765 53,845 38,974 Gain on former bank premises and equipment — (155 ) — (155 ) (50 ) Loss (Gain) on sale of securities 47 1 — 48 1 Gain on extinguishment of debt — (630 ) — (630 ) — Gain on branch sale (3,360 ) (3,360 ) Acquisition-related expenses (2) 570 679 419 1,249 1,134 Core conversion expenses 1,008 216 — 1,224 — Core pre-tax income 26,291 25,930 22,184 52,221 40,059 Provision for Income Taxes: (1) Provision for income taxes 5,923 5,276 4,559 11,199 8,198 Tax on gain on former bank premises and equipment — (33 ) — (33 ) (11 ) Tax on loss (gain) on sale of securities 10 — — 10 — Tax on gain on extinguishment of debt — (133 ) — (133 ) — Tax on gain on branch sale (833 ) (833 ) Tax on acquisition-related expenses (2) 103 143 2 246 91 Tax on core conversion expenses 213 46 — 259 — Core provision for income taxes 5,416 5,299 4,561 10,715 8,278 Preferred Dividends: Preferred dividends 1,350 1,350 1,350 2,700 2,700 Core preferred dividends 1,350 1,350 1,350 2,700 2,700 Net Income Available to Common Shareholders Net income available to common shareholders 20,753 19,193 15,856 39,946 28,076 Gain on former bank premises and equipment, net of tax — (122 ) — (122 ) (39 ) Loss (Gain) on sale of securities, net of tax 37 1 — 38 1 Gain on extinguishment of debt, net of tax — (497 ) — (497 ) — Gain on branch sale, net of tax (2,527 ) — (2,527 ) Acquisition-related expenses (2), net of tax 467 536 417 1,003 1,043 Core conversion expenses, net of tax 795 170 — 965 — Core net income available to common shareholders $ 19,525 $ 19,281 $ 16,273 $ 38,806 $ 29,081 Pre-tax, Pre-provision Earnings Available to Common Shareholders (a+b) $ 30,251 $ 28,631 $ 23,075 $ 58,882 $ 41,470 Gain on former bank premises and equipment — (155 ) — (155 ) (50 ) Loss (Gain) on sale of securities 47 1 — 48 1 Gain on extinguishment of debt — (630 ) — (630 ) — Gain on branch sale (3,360 ) (3,360 ) Acquisition-related expenses (2) 570 679 419 1,249 1,134 Core conversion expenses 1,008 216 — 1,224 — Core pre-tax, pre-provision earnings $ 28,516 $ 28,742 $ 23,494 $ 57,258 $ 42,555 Average Diluted Common Shares Outstanding 29,586,722 29,545,921 25,395,614 29,500,061 25,412,142 Diluted Earnings Per Common Share Diluted earnings per common share $ 0.70 $ 0.65 $ 0.62 $ 1.35 $ 1.10 Gain on former bank premises and equipment, net of tax — — — — — Loss (Gain) on sale of securities, net of tax — — — — — Gain on extinguishment of debt, net of tax — (0.02 ) — (0.02 ) — Gain on branch sale, net of tax (0.09 ) — (0.09 ) Acquisition-related expenses (2), net of tax 0.02 0.02 0.02 0.04 0.04 Core conversion expenses,net of tax 0.03 — — 0.03 — Core diluted earnings per common share $ 0.66 $ 0.65 $ 0.64 $ 1.31 $ 1.14 Pre-tax, Pre-provision Diluted Earnings per Common Share $ 1.02 $ 0.97 $ 0.91 $ 2.00 $ 1.63 Gain on former bank premises and equipment — (0.01 ) — (0.01 ) — Loss (gain) on sale of securities — — — — — Gain on extinguishment of debt — (0.02 ) — (0.02 ) — Gain on branch sale (0.11 ) — (0.11 ) Acquisition-related expenses (2) 0.02 0.02 0.02 0.04 0.04 Core conversion expenses 0.03 0.01 — 0.04 — Core pre-tax, pre-provision diluted earnings per common share $ 0.96 $ 0.97 $ 0.93 $ 1.94 $ 1.67 (1) Tax rates, exclusive of certain nondeductible merger-related expenses and goodwill, utilized were 21.129% for 2025 and 2024. These rates approximated the marginal tax rates. (2) Includes merger and conversion-related expenses and salary and employee benefits. (3) CECL non-purchased credit deteriorated (PCD) provision/unfunded commitment expense attributable to Oakwood

Business First Bancshares, Inc. Non-GAAP Measures (Unaudited) (Dollars in thousands, except per share data) June 30,

2025 March 31,

2025 June 30,

2024 Total Shareholders’ (Common) Equity: Total shareholders’ equity $ 848,440 $ 826,312 $ 664,530 Preferred stock (71,930 ) (71,930 ) (71,930 ) Total common shareholders’ equity 776,510 754,382 592,600 Goodwill (121,146 ) (121,691 ) (91,527 ) Core deposit and customer intangible (15,775 ) (16,538 ) (10,849 ) Total tangible common equity $ 639,589 $ 616,153 $ 490,224 Total Assets: Total assets $ 7,948,294 $ 7,784,728 $ 6,703,889 Goodwill (121,146 ) (121,691 ) (91,527 ) Core deposit and customer intangible (15,775 ) (16,538 ) (10,849 ) Total tangible assets $ 7,811,373 $ 7,646,499 $ 6,601,513 Common shares outstanding 29,602,970 29,572,297 25,502,175 Book value per common share $ 26.23 $ 25.51 $ 23.24 Tangible book value per common share $ 21.61 $ 20.84 $ 19.22 Common equity to total assets 9.77 % 9.69 % 8.84 % Tangible common equity to tangible assets 8.19 % 8.06 % 7.43 %

Business First Bancshares, Inc. Non-GAAP Measures (Unaudited) Three Months Ended Six Months Ended (Dollars in thousands, except per share data) June 30,

2025 March 31,

2025 June 30,

2024 June 30,

2025 June 30,

2024 Total Quarterly Average Assets $ 7,791,372 $ 7,750,982 $ 6,711,173 $ 7,771,289 $ 6,689,350 Total Quarterly Average Common Equity $ 765,884 $ 742,930 $ 583,184 $ 754,470 $ 580,414 Net Income Available to Common Shareholders: Net income available to common shareholders $ 20,753 $ 19,193 $ 15,856 $ 39,946 $ 28,076 CECL Oakwood impact (3), net of tax — — — — — Gain on former bank premises and equipment, net of tax — (122 ) — (122 ) (39 ) Loss (gain) on sale of securities, net of tax 37 1 — 38 1 Gain on extinguishment of debt, net of tax — (497 ) — (497 ) — Acquisition-related expenses, net of tax 467 — — 467 — Gain on branch sale, net of tax

(2,527 ) 536 417 (2,527 ) 1,043 Core conversion expenses, net of tax 795 170 — 965 — Core net income available to common shareholders $ 19,525 $ 19,281 $ 16,273 $ 38,806 $ 29,081 Return to common shareholders on average assets (annualized) (2) 1.07 % 1.00 % 0.95 % 1.04 % 0.84 % Core return on average assets (annualized) (2) 1.01 % 1.01 % 0.98 % 1.01 % 0.87 % Return to common shareholders on average common equity (annualized) (2) 10.87 % 10.48 % 10.94 % 10.68 % 9.73 % Core return on average common equity (annualized) (2) 10.23 % 10.53 % 11.22 % 10.37 % 10.08 % Interest Income: Interest income $ 114,850 $ 113,693 $ 99,870 $ 228,543 $ 195,881 Core interest income 114,850 113,693 99,870 228,543 195,881 Interest Expense: Interest expense 47,808 47,710 45,861 95,518 90,341 Core interest expense 47,808 47,710 45,861 95,518 90,341 Other Income: Other income 14,415 13,226 12,176 27,641 21,562 Gain on former bank premises and equipment — (155 ) — (155 ) (50 ) Loss (Gain) on sale of securities 47 1 — 48 1 Gain on extinguishment of debt — (630 ) — (630 ) — Gain on branch sale (3,360 ) (3,360 ) Core other income 11,102 12,442 12,176 23,544 21,513 Other Expense: Other expense 51,206 50,578 43,110 101,784 85,632 Acquisition-related expenses (570 ) (679 ) (419 ) (1,249 ) (1,134 ) Core conversion expenses (1,008 ) (216 ) — (1,224 ) — Core other expense $ 49,628 $ 49,683 $ 42,691 $ 99,311 $ 84,498 Efficiency Ratio: Other expense (a) $ 51,206 $ 50,578 $ 43,110 $ 101,784 $ 85,632 Core other expense (c) $ 49,628 $ 49,683 $ 42,691 $ 99,311 $ 84,498 Net interest and other income (1) (b) $ 81,505 $ 79,210 $ 66,185 $ 160,714 $ 127,103 Core net interest and other income (1) (d) $ 78,144 $ 78,425 $ 66,185 $ 156,569 $ 127,053 Efficiency ratio (a/b) 62.83 % 63.85 % 65.14 % 63.33 % 67.37 % Core efficiency ratio (c/d) 63.51 % 63.35 % 64.50 % 63.43 % 66.51 % Total Average Interest-Earnings Assets $ 7,299,899 $ 7,263,399 $ 6,291,616 $ 7,281,750 $ 6,268,873 Net Interest Income: Net interest income $ 67,042 $ 65,983 $ 54,009 $ 133,025 $ 105,540 Loan discount accretion $ (767 ) $ (793 ) $ (1,695 ) $ (1,560 ) $ (2,480 ) Net interest income excluding loan discount accretion $ 66,275 $ 65,190 $ 52,314 $ 131,465 $ 103,060 Net interest margin (2) 3.68 % 3.68 % 3.45 % 3.68 % 3.39 % Net interest margin excluding loan discount accretion (2) 3.64 % 3.64 % 3.34 % 3.64 % 3.31 % Net interest spread (2) 2.88 % 2.91 % 2.47 % 2.90 % 2.42 % Net interest spread excluding loan discount accretion (2) 2.84 % 2.86 % 2.37 % 2.85 % 2.34 % (1) Excludes gains/losses on sales of securities. (2) Calculated utilizing an actual day count convention. (3) CECL non-PCD provision/unfunded commitment expense attributable to Oakwood