Atlantic Capital Bancshares (ACBI) 8-K Results of Operations and Financial Condition

Exhibit 99.1

Exhibit 99.1 PRESS RELEASE ATLANTIC CAPITAL BANCSHARES, INC. REPORTS FIRST QUARTER 2021 RESULTS Atlanta, GA – April 22, 2021 – Atlantic Capital Bancshares, Inc. (NASDAQ: ACBI) announced net income for the quarter ended March 31, 2021 of $13.4 million, or $0.65 per diluted share, compared to $2.2 million, or $0.10 per diluted share, for the first quarter of 2020 and $10.0 million, or $0.48 per diluted share, for the fourth quarter of 2020. “Atlantic Capital reported another quarter of strong revenue growth despite lower interest rates and soft loan demand. As the economic recovery has gained strength, our borrowers’ performance has improved which has resulted in a reduction in the allowance for credit losses. We anticipate these trends in revenue growth and credit quality improvement to continue over the balance of the year,” remarked Douglas Williams, President and Chief Executive Officer. First Quarter Highlights(1)  Total assets of $3.7 billion, compared to $3.6 billion at December 31, 2020 and $2.7 billion at March 31, 2020.  Loans held for investment increased $51.2 million, or 9% annualized, from December 31, 2020 and increased $367.9 million, or 19%, from March 31, 2020.  Quarterly average deposits increased $282.5 million, or 39% annualized, compared to the fourth quarter of 2020 and increased $902.4 million, or 40%, compared to the first quarter of 2020.  Cost of deposits decreased to 0.12% from 0.16% in the fourth quarter of 2020 and from 0.75% in the first quarter of 2020.  Tangible book value per share increased to $15.74 from $15.62 at December 31, 2020 and from $14.54 at March 31, 2020.  Annualized net charge-offs to average loans totaled 0.04% for the first quarter of 2021 and non-performing assets to total assets were 0.06% at March 31, 2021.  The allowance for credit losses was 1.31% of total loans held for investment at March 31, 2021, compared to 1.55% at December 31, 2020.  Repurchased 222,000 shares in the first quarter of 2021 totaling $4.2 million at an average price of $18.87. As of March 31, 2021, approximately $3.1 million remained from our $25 million share repurchase program. Income Statement Taxable equivalent net interest income totaled $23.7 million for the first quarter of 2021, an increase of $2.5 million, or 12%, from the first quarter of 2020, and an increase of $721,000, or 13% annualized, from the fourth quarter of 2020. The first quarter of 2021 included $2.2 million in Paycheck Protection Program (“PPP”) loan income compared to $2.3 million in the fourth quarter of 2020. Taxable equivalent net interest margin was 2.81% in the first quarter of 2021, compared to 3.41% in the first quarter of 2020 and 2.91% in the fourth quarter of 2020. The linked quarter decrease in net interest margin was primarily due to the impact of the increase in deposits and corresponding increase in cash balances. The yield on loans in the first quarter of 2021 was 3.89%, a decrease of 88 basis points from the first quarter of 2020 and unchanged from the fourth quarter of 2020. Excluding the PPP loans, the first quarter of 2021 loan yield was 3.83%, a decrease of 3 basis points compared to the fourth quarter of 2020. The cost of deposits in the first quarter of 2021 was 0.12%, a decrease of 63 basis points from the first quarter of 2020 and a decrease of 4 basis points from the fourth quarter of 2020. The cost of interest bearing deposits decreased 90 basis points to 0.19% from the first quarter of 2020, and decreased 6 basis points from the fourth quarter of 2020. In the first quarter of 2021, we recorded a negative provision for credit losses of $4.5 million compared to a provision for credit losses of $8.1 million in the first quarter of 2020 and $481,000 in the fourth quarter of 2020. The first quarter of (1) Commentary is on a fully taxable-equivalent basis unless otherwise noted. Consistent with SEC guidance in Industry Guide 3 that contemplates the calculation of tax-exempt income on a tax equivalent basis, net interest income and net interest margin are provided on a fully taxable-equivalent basis, which generally assumes a 21% marginal tax rate. We provide detailed reconciliations in the Non-GAAP Performance and Financial Measures Reconciliation table on page 11.

2021 provision for credit losses included a negative provision for loan losses of $4.1 million and a negative provision for unfunded commitments of $445,000. Noninterest income totaled $3.6 million in the first quarter of 2021 compared to $2.4 million in the first quarter of 2020 and $3.0 million in the fourth quarter of 2020. Service charge income in the first quarter of 2021 totaled $1.7 million, an increase of $431,000 compared to the first quarter of 2020, and an increase of $322,000 from the fourth quarter of 2020. The increase in service charge income was primarily due to growth in our payments, fintech and private capital solution businesses. SBA income in the first quarter of 2021 totaled $1.2 million, compared to $414,000 in the first quarter of 2020 and $1.0 million in the fourth quarter of 2020. The increase was primarily from higher SBA origination volume and higher SBA premiums in the secondary market. Noninterest expense totaled $15.1 million in the first quarter of 2021, compared to $12.9 million in the first quarter of 2020 and $13.2 million in the fourth quarter of 2020. Salaries and employee benefits expense totaled $10.4 million in the first quarter of 2021, an increase of $2.0 million compared to the fourth quarter of 2020. Salaries and employee benefits expense in the first quarter of 2021 included approximately a $700,000 seasonal increase in benefit costs and $255,000 in contract labor expense for PPP round two loan processing. In addition, the first quarter of 2021 included an increase in short-term and long-term incentive costs, along with the partial impact of eight net new hires and merit increases during the quarter. Professional services expense in the first quarter totaled $922,000 and included approximately $200,000 in consulting expense for PPP round two loan processing and PPP round one loan forgiveness. Balance Sheet Total loans held for investment were $2.3 billion at March 31, 2021, an increase of $367.9 million, or 19%, from March 31, 2020 and an increase of $51.8 million, or 9% annualized, from December 31, 2020. PPP loans totaled $218.8 million at March 31, 2021, an increase of $26.6 million compared to December 31, 2020, and included $72.8 million in new round two PPP loans offset by $46.2 million in forgiven round one PPP loans. The allowance for credit losses was 1.31% of total loans held for investment at March 31, 2021, compared to 1.55% at December 31, 2020. The decrease in the allowance was a result of an improvement in the new Current Expected Credit Losses, or CECL economic forecast along with credit rating upgrades for criticized and classified loans. Excluding the impact of PPP loans, the allowance for credit losses at March 31, 2021 was 1.45%, compared to 1.70% at December 31, 2020. Total average deposits were $3.2 billion for the first quarter of 2021, an increase of $902.4 million, or 40%, from the first quarter of 2020 and an increase of $282.5 million, or 39% annualized, from the fourth quarter of 2020. Average noninterest bearing deposits were $1.1 billion for the first quarter of 2021, an increase of $423.5 million, or 59%, from the first quarter of 2020 and an increase of $159.5 million, or 66% annualized, from the fourth quarter of 2020. Noninterest bearing deposits were 36.0% of total average deposits in the first quarter of 2021, compared to 31.6% in the first quarter of 2020 and 34.0% in the fourth quarter of 2020. Tangible common equity to tangible assets decreased to 8.6% at March 31, 2021 compared to 8.9% at December 31, 2020, due to the impact from the first quarter growth in deposits and its corresponding increase on the level of total tangible assets. Cash and cash equivalents were $645.8 million and total assets were $3.7 billion at March 31, 2021 compared to cash and cash equivalents of $142.4 million and total assets of $2.7 billion at March 31, 2020. Earnings Conference Call Atlantic Capital will host a conference call at 1:00 p.m. ET on Friday, April 23, 2021, to discuss the financial results for the quarter ended March 31, 2021. Individuals wishing to participate in the conference call may do so by dialing 833-685- 0902 from the United States. The call will also be available live via webcast on the Investor Relations page of our website, www.atlanticcapitalbank.com. A presentation will be used during the earnings conference call and is available at https://atlanticcapitalbank.q4ir.com/news-market-data/presentations/default.aspx. 2

Non-GAAP Financial Me asures Statements included in this press release include non-GAAP financial measures and should be read along with the accompanying tables, which provide a reconciliation of non-GAAP financial measures to GAAP financial measures. Atlantic Capital management uses non-GAAP financial measures, including: (i) taxable equivalent interest income; (ii) taxable equivalent net interest income; (iii) loan yield excluding PPP loans; (iv) taxable equivalent net interest margin; (v) taxable equivalent net interest margin excluding PPP loans; (vi) taxable equivalent income before income taxes; (vii) taxable equivalent income tax expense; (viii) tangible common equity to tangible assets; (ix) tangible book value per common share, and (x) allowance for credit losses to loans held for investment excluding PPP loans, in our analysis of the Company's performance. Tangible common equity excludes goodwill from shareholders' equity. Management believes that non-GAAP financial measures provide a greater understanding of ongoing performance and operations and enhance comparability with prior periods. Non-GAAP financial measures should not be considered as an alternative to any measure of performance or financial condition as determined in accordance with GAAP, and investors should consider Atlantic Capital’s performance and financial condition as reported under GAAP and all other relevant information when assessing the performance or financial condition of the Company. Non-GAAP financial measures have limitations as analytical tools, and investors should not consider them in isolation or as a substitute for analysis of the results or financial condition as reported under GAAP. Non-GAAP financial measures may not be comparable to non- GAAP financial measures presented by other companies. Forward-Looking Statements This press release contains “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 represent plans, estimates, objectives, goals, guidelines, expectations, intentions, projections and statements of our beliefs concerning future events, business plans, objectives, expected operating results and the assumptions upon which those statements are based. Forward-looking statements include without limitation, any statement that may predict, forecast, indicate or imply future results, performance or achievements, and are typically id entified with words such as “may,” “could,” “should,” “will,” “would,” “believe,” “anticipate,” “estimate,” “project,” “expect,” “intend,” “plan,” “strive,” or words or phases of similar meaning. Forward-looking statements may include, among other things, statements about Atlantic Capital’s confidence in its strategies and its expectations about financial performance, the impact of COVID-19 on operations, market growth, market and regulatory trends and developments, acquisitions and divestitures, new technologies, services and opportunities and earnings. The forward-looking statements are based largely on Atlantic Capital’s expectations and are subject to a number of known and unknown risks and uncertainties that are subject to change based on factors which are, in many instances, beyond Atlantic Capital’s control. Atlantic Capital undertakes no obligation to publicly update any forward-looking statement to reflect developments occurring after the statement is made, except as otherwise required by law. Actual results, performance or achievements could differ materially from those contemplated, expressed, or implied by the forward-looking statements as a result of, among other factors, the risks and uncertainties described in “Risk Factors” and “Management’s Discussion and Analysis of Financial Condition and Results of Operations” in Atlantic Capital’s Annual Report on Form 10-K. Please refer to the SEC’s website at www.sec.gov where you can review those documents. About Atlantic Capital Bancshares Atlantic Capital Bancshares, Inc. is a $3.7 billion publicly traded bank holding company headquartered in Atlanta, Georgia. Atlantic Capital offers commercial and not-for-profit banking services, specialty corporate financial services, private banking services and commercial real estate finance solutions to privately held companies and individuals in the Atlanta area, as well as payments and other specialized financial services for select clients nationally. Media Contact: Financial Contact: Ashley Carson Patrick Oakes Email: ashley.carson@atlcapbank.com Email: patrick.oakes@atlcapbank.com Phone: 404-995-6050 Phone: 404-995-6050 (ACB-ER) 3

ATLANTIC CAPITAL BANCSHARES, INC. Selected Financial Information (in thousands, except share and per share data; taxable equivalent) INCOME SUMMARY Interest income - taxable equivalent (1) $ 25,775 $ 25,288 $ 24,578 $ 24,151 $ 26,246 (2) % Interest expense 2,065 2,299 2,515 2,166 5,043 (59) Net interest income - taxable equivalent 23,710 22,989 22,063 21,985 21,203 12 Provision for credit losses (4,519) 481 28 8,863 8,074 (156) Net interest income after provision for credit losses 28,229 22,508 22,035 13,122 13,129 115 Noninterest income 3,562 3,016 2,504 2,343 2,422 47 Noninterest expense 15,149 13,164 13,713 12,904 12,877 18 Income before income taxes 16,642 12,360 10,826 2,561 2,674 522 Income tax expense 3,280 2,410 2,208 712 550 496 Net income(1)(2) $ 13,362 $ 9,950 $ 8,618 $ 1,849 $ 2,124 529 % PER SHARE DATA Diluted earnings per share $ 0.65 $ 0.48 $ 0.40 $ 0.09 $ 0.10 Book value per share 16.72 16.60 16.05 15.64 15.47 Tangible book value per common share (2) 15.74 15.62 15.11 14.72 14.54 PERFORMANCE MEASURES Return on average equity 15.99 % 11.68 % 10.05 % 2.20 % 2.56 % Return on average assets 1.50 1.19 1.15 0.25 0.32 Taxable equivalent net interest margin 2.81 2.91 3.14 3.23 3.41 Taxable equivalent net interest margin excluding PPP loans 2.70 2.81 3.18 3.35 3.41 Efficiency ratio 56.30 51.30 56.61 53.82 55.03 Average loans to average deposits 71.93 76.81 88.65 88.46 83.84 CAPITAL Average equity to average assets 9.39 % 10.18 % 11.45 % 11.53 % 12.41 % Tangible common equity to tangible assets 8.63 8.86 11.03 11.01 11.57 Leverage ratio 8.4 (3) 8.9 9.9 9.9 10.7 Total risk based capital ratio 16.4 (3) 16.1 16.9 14.8 14.9 SHARES OUTSTANDING Number of common shares outstanding - basic 20,354,077 20,394,912 21,202,783 21,477,631 21,479,986 Number of common shares outstanding - diluted 20,617,188 20,492,542 21,298,098 21,569,050 21,675,934 Average number of common shares - basic 20,380,066 20,711,089 21,500,735 21,472,462 21,689,038 Average number of common shares - diluted 20,502,184 20,795,332 21,543,805 21,535,040 21,842,175 ASSET QUALITY Allowance for credit losses to loans held for investment 1.31 % 1.55 % 1.59 % 1.61 % 1.43 % Net charge-offs to average loans (4) 0.04 0.05 0.06 0.29 0.04 Non-performing assets to total assets 0.06 0.13 0.20 0.24 0.27 AVERAGE BALANCES Total loans $ 2,270,660 $ 2,207,956 $ 2,191,669 $ 2,131,847 $ 1,890,184 Investment securities 579,547 491,134 453,382 462,850 417,971 Total assets 3,611,417 3,328,719 2,977,444 2,932,716 2,686,266 Deposits 3,156,906 2,874,402 2,472,218 2,409,958 2,254,505 Shareholders' equity 338,990 338,948 341,017 338,027 333,480 AT PERIOD END Loans and loans held for sale $ 2,302,661 $ 2,249,036 $ 2,188,894 $ 2,185,847 $ 1,932,909 Investment securities 613,236 535,579 446,706 457,749 466,405 Total assets 3,732,668 3,615,617 2,923,977 2,890,622 2,719,658 Deposits 3,277,692 3,161,508 2,468,722 2,407,631 2,225,119 Shareholders’ equity 340,328 338,586 340,309 335,980 332,300 (1)Interest income on tax-exempt securities has been increased to reflect comparable interest on taxable securities. The rate used was 21%, reflecting the statutory federal income tax rate. (2)Excludes effect of acquisition related intangibles. (3)Amounts are estimates as of March 31, 2021. (4)Annualized. Quarter Quarter Quarter Third Quarter First 2021 2020 to 2020 Quarter First Quarter 2021 First Fourth Second 4

ATLANTIC CAPITAL BANCSHARES, INC. Consolidated Balance Sheets (unaudited) (in thousands, except share data) ASSETS Cash and due from banks $ 32,850 $ 16,865 $ 27,536 Interest-bearing deposits in banks 612,966 636,537 114,829 Cash and cash equivalents 645,816 653,402 142,365 Investment securities available for sale 390,701 335,423 280,390 Investment securities held to maturity, net of allowance for credit losses of $14 at March 31, 2021, December 31, 2020 and March 31, 2020, respectively 222,535 200,156 186,015 Other investments 24,709 25,892 27,140 Loans held for sale 1,847 — — Loans held for investment 2,300,814 2,249,036 1,932,909 Less: allowance for loan losses (27,506) (31,818) (24,896) Loans held for investment, net 2,273,308 2,217,218 1,908,013 Premises and equipment, net 20,633 21,589 22,533 Bank owned life insurance 73,223 72,856 66,761 Goodwill 19,925 19,925 19,925 Other intangibles, net 2,688 2,731 2,785 Other real estate owned 16 16 779 Other assets 57,267 66,409 62,952 Total assets $ 3,732,668 $ 3,615,617 $ 2,719,658 LIABILITIES AND SHAREHOLDERS’ EQUITY Deposits: Noninterest-bearing demand $ 1,280,524 $ 1,033,765 $ 712,919 Interest-bearing checking 485,540 760,638 368,463 Savings 562 625 567 Money market 1,142,361 1,030,753 982,109 Time 294,129 241,328 66,793 Brokered deposits 74,576 94,399 94,268 Total deposits 3,277,692 3,161,508 2,225,119 Federal funds purchased — — 75,000 Long-term debt 73,878 73,807 49,916 Other liabilities 40,770 41,716 37,323 Total liabilities 3,392,340 3,277,031 2,387,358 SHAREHOLDERS’ EQUITY Preferred stock, no par value; 10,000,000 shares authorized; no shares issued and outstanding as of March 31, 2021, December 31, 2020 and March 31, 2020 — — — Common stock, no par value; 100,000,000 shares authorized; 20,354,077, 20,394,912, and 21,479,986 shares issued and outstanding as of March 31, 2021, December 31, 2020 and March 31, 2020, respectively 207,047 209,942 224,233 Retained earnings 127,499 114,137 93,721 Accumulated other comprehensive income 5,782 14,507 14,346 Total shareholders’ equity 340,328 338,586 332,300 TOTAL LIABILITIES AND SHAREHOLDERS’ EQUITY $ 3,732,668 $ 3,615,617 $ 2,719,658 March 31, 2021 March 31, 2020 December 31, 2020 5

ATLANTIC CAPITAL BANCSHARES, INC. Consolidated Statements of Income (unaudited) (in thousands, except share and per share data) INTEREST INCOME Loans, including fees $ 21,769 $ 21,609 $ 21,049 $ 20,496 $ 22,426 Investment securities 3,374 3,000 2,910 3,041 2,732 Interest and dividends on other interest‑earning assets 267 334 274 260 865 Total interest income 25,410 24,943 24,233 23,797 26,023 INTEREST EXPENSE Interest on deposits 971 1,188 1,151 1,299 4,182 Interest on Federal Home Loan Bank advances — — 16 38 — Interest on federal funds purchased and securities sold under agreements to repurchase — — 3 6 32 Interest on long-term debt 1,094 1,111 1,345 823 829 Total interest expense 2,065 2,299 2,515 2,166 5,043 NET INTEREST INCOME BEFORE PROVISION FOR CREDIT LOSSES 23,345 22,644 21,718 21,631 20,980 Provision for credit losses (4,519) 481 28 8,863 8,074 NET INTEREST INCOME AFTER PROVISION FOR CREDIT LOSSES 27,864 22,163 21,690 12,768 12,906 NONINTEREST INCOME Service charges 1,663 1,341 1,217 1,081 1,232 Gains (losses) on sale of securities 2 (23) — — — (Losses) gains on sale of other assets — (6) (145) — 5 Derivatives income (loss) 47 11 10 (10) 246 Bank owned life insurance 391 368 363 367 362 SBA lending activities 1,225 1,015 893 782 414 Other noninterest income 234 310 166 123 163 Total noninterest income 3,562 3,016 2,504 2,343 2,422 NONINTEREST EXPENSE Salaries and employee benefits 10,421 8,437 8,850 8,466 8,476 Occupancy 734 767 739 883 794 Equipment and software 774 969 826 763 779 Professional services 922 686 562 792 705 Communications and data processing 792 789 757 670 897 Marketing and business development 108 144 141 79 153 Travel, meals and entertainment 10 14 39 34 140 FDIC premiums 275 241 213 175 — Other noninterest expense 1,113 1,117 1,586 1,042 933 Total noninterest expense 15,149 13,164 13,713 12,904 12,877 INCOME BEFORE PROVISION FOR INCOME TAXES 16,277 12,015 10,481 2,207 2,451 Provision for income taxes 2,915 2,065 1,863 358 327 NET INCOME $ 13,362 $ 9,950 $ 8,618 $ 1,849 $ 2,124 Net income per common share - basic $ 0.66 $ 0.48 $ 0.40 $ 0.09 $ 0.10 Net income per common share - diluted $ 0.65 $ 0.48 $ 0.40 $ 0.09 $ 0.10 Weighted average shares - basic 20,380,066 20,711,089 21,500,735 21,472,462 21,689,038 Weighted average shares - diluted 20,502,184 20,795,332 21,543,805 21,535,040 21,842,175 Three months ended 2020 March 31, 2021 September 30, 2020 March 31, 2020 June 30, December 31, 2020 6

ATLANTIC CAPITAL BANCSHARES, INC. Average Balance Sheets and Net Interest Margin Analysis Selected Financial Information Tax Tax Equivalent Equivalent (dollars in thousands; taxable equivalent) Yield/Rate Yield/Rate Assets Interest bearing deposits in other banks $ 561,809 $ 168 0.12 % $ 435,939 $ 141 0.13 % Investment securities: Taxable investment securities 356,250 1,898 2.16 275,872 1,587 2.29 Non-taxable investment securities (1) 223,297 1,841 3.34 215,262 1,758 3.25 Total investment securities 579,547 3,739 2.62 491,134 3,345 2.71 Loans 2,270,660 21,769 3.89 2,207,956 21,609 3.89 FHLB and FRB stock 12,701 99 3.17 12,699 193 6.05 Total interest-earning assets 3,424,717 25,775 3.05 3,147,728 25,288 3.20 Non-earning assets 186,700 180,991 Total assets $ 3,611,417 $ 3,328,719 Liabilities Interest bearing deposits: NOW, money market, and savings 1,662,097 834 0.20 1,585,928 1,043 0.26 Time deposits 273,615 74 0.11 221,792 72 0.13 Brokered deposits 84,663 63 0.30 89,673 73 0.32 Total interest-bearing deposits 2,020,375 971 0.19 1,897,393 1,188 0.25 Total long-term debt 73,830 1,094 6.01 73,811 1,111 5.99 Total interest-bearing liabilities 2,094,205 2,065 0.40 1,971,204 2,299 0.46 Demand deposits 1,136,531 977,009 Other liabilities 41,691 41,558 Shareholders’ equity 338,990 338,948 Total liabilities and shareholders’ equity $ 3,611,417 $ 3,328,719 Net interest spread 2.65 % 2.73 % Net interest income and net interest margin (2) $23,710 2.81 % $ 22,989 2.91 % Non-taxable equivalent net interest margin 2.76 % 2.86 % Tax Tax Equivalent Equivalent (dollars in thousands; taxable equivalent) Yield/Rate Yield/Rate Assets Interest bearing deposits in other banks $ 561,809 $ 168 0.12 % $ 177,063 $ 668 1.52 % Other short-term investments — — — 110 — — Investment securities: Taxable investment securities 356,250 1,898 2.16 253,937 1,680 2.66 Non-taxable investment securities (1) 223,297 1,841 3.34 164,034 1,275 3.13 Total investment securities 579,547 3,739 2.62 417,971 2,955 2.84 Loans 2,270,660 21,769 3.89 1,890,184 22,426 4.77 FHLB and FRB stock 12,701 99 3.17 12,678 197 6.25 Total interest-earning assets 3,424,717 25,775 3.05 2,498,006 26,246 4.23 Non-earning assets 186,700 188,260 Total assets $ 3,611,417 $ 2,686,266 Liabilities Interest bearing deposits: NOW, money market, and savings 1,662,097 834 0.20 1,393,541 3,767 1.09 Time deposits 273,615 74 0.11 55,775 52 0.37 Brokered deposits 84,663 63 0.30 92,188 363 1.58 Total interest-bearing deposits 2,020,375 971 0.19 1,541,504 4,182 1.09 Total borrowings — — — 11,703 32 1.10 Total long-term debt 73,830 1,094 6.01 49,888 829 6.68 Total interest-bearing liabilities 2,094,205 2,065 0.40 1,603,095 5,043 1.27 Demand deposits 1,136,531 713,001 Other liabilities 41,691 36,690 Shareholders’ equity 338,990 333,480 Total liabilities and shareholders’ equity $ 3,611,417 $ 2,686,266 Net interest spread 2.65 % 2.96 % Net interest income and net interest margin (2) $23,710 2.81 % $ 21,203 3.41 % Non-taxable equivalent net interest margin 2.76 % 3.38 % Interest Income/ Expense Three months ended March 31, 2021 March 31, 2020 Interest Income/ Expense Average Balance Average Balance Three months ended December 31, 2020 Interest Income/ Expense Interest Income/ Expense March 31, 2021 Average Balance Average Balance (1) Interest revenue on tax-exempt securities has been increased to reflect comparable interest on taxable securities. The rate used was 21%, reflecting the statutory federal income tax rate. (2) Tax equivalent net interest income divided by total interest-earning assets using the appropriate day count convention based on the type of interest-earning asset. (1) Interest revenue on tax-exempt securities has been increased to reflect comparable interest on taxable securities. The rate used was 21%, reflecting the statutory federal income tax rate. (2) Tax equivalent net interest income divided by total interest-earning assets using the appropriate day count convention based on the type of interest-earning asset. 7

ATLANTIC CAPITAL BANCSHARES, INC. Period End Loans (dollars in thousands) Loans held for sale Loans held for sale $ 1,847 $ — $ 859 $ 1,153 $ — $ 1,847 $ 1,847 Total loans held for sale $ 1,847 $ — $ 859 $ 1,153 $ — $ 1,847 $ 1,847 Loans held for investment Commercial loans: Commercial and industrial - other $ 735,287 $ 760,645 $ 712,567 $ 739,769 $ 760,062 $ (25,358) $ (24,775) Commercial and industrial - PPP 218,766 192,160 231,834 234,049 — 26,606 218,766 Commercial real estate: Multifamily 80,507 66,262 58,336 58,909 73,654 14,245 6,853 Owner occupied 381,018 373,689 364,170 366,847 359,026 7,329 21,992 Investment 480,566 469,150 458,279 474,565 477,451 11,416 3,115 Construction and land: 1‑4 family residential construction 1,578 1,171 — 11 2,706 407 (1,128) Other construction, development, and land 141,218 144,424 139,836 128,980 124,116 (3,206) 17,102 Total commercial loans 2,038,940 2,007,501 1,965,022 2,003,130 1,797,015 31,439 241,925 Residential: Residential mortgages 31,817 33,783 29,460 32,327 31,761 (1,966) 56 Home equity 26,293 25,443 24,528 23,689 23,479 850 2,814 Total residential loans 58,110 59,226 53,988 56,016 55,240 (1,116) 2,870 Consumer 203,176 176,066 154,916 113,149 58,164 27,110 145,012 Other 7,689 13,897 22,777 22,160 25,488 (6,208) (17,799) 2,307,915 2,256,690 2,196,703 2,194,455 1,935,907 51,225 372,008 Less net deferred fees and other unearned income (7,101) (7,654) (8,668) (9,761) (2,998) 553 (4,103) Total loans held for investment $ 2,300,814 $ 2,249,036 $ 2,188,035 $ 2,184,694 $ 1,932,909 $ 51,778 $ 367,905 Total loans $ 2,302,661 $ 2,249,036 $ 2,188,894 $ 2,185,847 $ 1,932,909 $ 53,625 $ 369,752 Total unfunded commitments $ 789,869 $ 813,757 $ 764,247 $ 749,321 $ 689,620 $ (23,888) $ 100,249 Year Over Year Change 2020 Linked Quarter Change March 31, March 31, 2021 September 30, 2020 June 30, 2020 December 31, 2020 8

ATLANTIC CAPITAL BANCSHARES, INC. Allowance for Credit Losses Activity and Credit Quality (dollars in thousands) Allowance for loan losses Balance at beginning of period $ 31,818 $ 31,894 $ 31,605 $ 24,896 $ 18,535 Adoption of ASU 2016-13 — — — — (854) Provision for loan losses (4,074) 225 636 8,222 7,409 Loans charged-off: Commercial and industrial (288) (401) (404) (1,479) (18) Commercial real estate — — — — (78) Construction and land — — — — — Residential mortgages — — — (36) — Home equity — — — — (125) Consumer — — — — — Other — — — — — Total loans charged-off (288) (401) (404) (1,515) (221) Recoveries on loans previously charged-off: Commercial and industrial 50 37 56 1 — Commercial real estate — 44 — — 18 Construction and land — 18 — — — Residential mortgages — — — — 1 Home equity — — — — — Consumer — 1 1 1 8 Other — — — — — Total recoveries 50 100 57 2 27 Net charge-offs $ (238) $ (301) $ (347) $ (1,513) $ (194) Balance at period end $ 27,506 $ 31,818 $ 31,894 $ 31,605 $ 24,896 Allowance for unfunded commitments Balance at beginning of period $ 3,128 $ 2,871 $ 3,480 $ 2,838 $ 892 Adoption of ASU 2016-13 — — — — 1,275 Provision for unfunded commitments (445) 257 (609) 642 671 Balance at period end $ 2,683 $ 3,128 $ 2,871 $ 3,480 $ 2,838 Total allowance for credit losses - loans and unfunded commitments $ 30,189 $ 34,946 $ 34,765 $ 35,085 $ 27,734 Provision for credit losses under CECL Provision for loan losses (4,074) 225 636 8,222 7,409 Provision for securities held to maturity credit losses - (1) 1 (1) (6) Provision for unfunded commitments (445) 257 (609) 642 671 Total provision for credit losses $ (4,519) $ 481 $ 28 $ 8,863 $ 8,074 Non-performing loans $ 2,056 $ 4,862 $ 5,421 $ 6,265 $ 6,515 Foreclosed properties (OREO) 16 16 563 779 779 Total nonperforming assets $ 2,072 $ 4,878 $ 5,984 $ 7,044 $ 7,294 Allowance for loan losses to loans held for investment 1.20 % 1.41 % 1.46 % 1.45 % 1.29 % Allowance for credit losses to loans held for investment 1.31 % 1.55 % 1.59 % 1.61 % 1.43 % Allowance for credit losses to loans held for investment excluding PPP loans 1.45 % 1.70 % 1.78 % 1.80 % 1.43 % Net charge-offs to average loans (1) 0.04 0.05 0.06 0.29 0.04 Non-performing loans as a percentage of total loans 0.09 % 0.22 % 0.25 % 0.29 % 0.34 % Non-performing assets as a percentage of total assets 0.06 % 0.13 % 0.20 % 0.24 % 0.27 % (1)Annualized. Third Quarter Second Quarter Quarter First 2020 First Quarter Fourth Quarter 2021 9

ATLANTIC CAPITAL BANCSHARES, INC. Period End Deposits (dollars in thousands) DDA $ 1,280,524 $ 1,033,765 $ 843,656 $ 883,662 $ 712,919 $ 246,759 $ 567,605 NOW 485,540 760,638 387,858 449,737 368,463 (275,098) 117,077 Savings 562 625 568 583 567 (63) (5) Money market 1,142,361 1,030,753 945,834 879,863 982,109 111,608 160,252 Time 294,129 241,328 196,343 131,353 66,793 52,801 227,336 Brokered 74,576 94,399 94,463 62,433 94,268 (19,823) (19,692) Total deposits $ 3,277,692 $ 3,161,508 $ 2,468,722 $ 2,407,631 $ 2,225,119 $ 116,184 $ 1,052,573 Average Deposits (dollars in thousands) DDA $ 1,136,531 $ 977,009 $ 854,715 $ 815,299 $ 713,001 $ 159,522 $ 423,530 NOW 618,701 558,967 440,734 462,051 382,178 59,734 236,523 Savings 587 614 586 574 650 (27) (63) Money market 1,042,809 1,026,347 942,062 952,444 1,010,713 16,462 32,096 Time 273,615 221,792 166,019 96,362 55,775 51,823 217,840 Brokered 84,663 89,673 68,102 83,228 92,188 (5,010) (7,525) Total deposits $ 3,156,906 $ 2,874,402 $ 2,472,218 $ 2,409,958 $ 2,254,505 $ 282,504 $ 902,401 Noninterest bearing deposits as a percentage of average deposits 36.0 % 34.0 % 34.6 % 33.8 % 31.6 % Cost of interest-bearing deposits 0.19 % 0.25 % 0.28 % 0.33 % 1.09 % Cost of deposits 0.12 % 0.16 % 0.19 % 0.22 % 0.75 % Change Q1 2020 Quarter Quarter Quarter Quarter Quarter Quarter Q1 2021 vs First Fourth Third Second First Linked 2021 2020 March 31, 2021 Year Over Year Change 2020 December 31, June 30, 2020 2020 March 31, September 30, 2020 Linked Quarter Change 10

ATLANTIC CAPITAL BANCSHARES, INC. Non-GAAP Performance and Financial Measures Reconciliation (in thousands, except share and per share data) Taxable equivalent interest income reconciliation Interest income - GAAP $ 25,410 $ 24,943 $ 24,233 $ 23,797 $ 26,023 Taxable equivalent adjustment 365 345 345 354 223 Interest income - taxable equivalent $ 25,775 $ 25,288 $ 24,578 $ 24,151 $ 26,246 Taxable equivalent net interest income reconciliation Net interest income - GAAP $ 23,345 $ 22,644 $ 21,718 $ 21,631 $ 20,980 Taxable equivalent adjustment 365 345 345 354 223 Net interest income - taxable equivalent $ 23,710 $ 22,989 $ 22,063 $ 21,985 $ 21,203 Loan yield excluding PPP loans reconciliation Loan yield - GAAP 3.89 % 3.89 % 3.82 % 3.87 % 4.77 % Impact of PPP loans (0.06) (0.03) 0.13 0.22 — Loan yield excluding PPP loans 3.83 % 3.86 % 3.95 % 4.09 % 4.77 % Taxable equivalent net interest margin reconciliation Net interest margin - GAAP 2.76 % 2.86 % 3.09 % 3.17 % 3.38 % Impact of taxable equivalent adjustment 0.05 0.05 0.05 0.06 0.03 Net interest margin - taxable equivalent 2.81 % 2.91 % 3.14 % 3.23 % 3.41 % Taxable equivalent net interest margin excluding PPP loans reconciliation Net interest margin - taxable equivalent 2.81 % 2.91 % 3.14 % 3.23 % 3.41 % Impact of PPP loans (0.11) (0.10) 0.04 0.12 — Net interest margin - taxable equivalent excluding PPP loans 2.70 % 2.81 % 3.18 % 3.35 % 3.41 % Taxable equivalent income before income taxes reconciliation Income before income taxes - GAAP $ 16,277 $ 12,015 $ 10,481 $ 2,207 $ 2,451 Taxable equivalent adjustment 365 345 345 354 223 Income before income taxes $ 16,642 $ 12,360 $ 10,826 $ 2,561 $ 2,674 Taxable equivalent income tax expense reconciliation Income tax expense - GAAP $ 2,915 $ 2,065 $ 1,863 $ 358 $ 327 Taxable equivalent adjustment 365 345 345 354 223 Income tax expense $ 3,280 $ 2,410 $ 2,208 $ 712 $ 550 Tangible book value per common share reconciliation Total shareholders’ equity $ 340,328 $ 338,586 $ 340,309 $ 335,980 $ 332,300 Intangible assets (19,925) (19,925) (19,925) (19,925) (19,925) Total tangible common equity $ 320,403 $ 318,661 $ 320,384 $ 316,055 $ 312,375 Common shares outstanding 20,354,077 20,394,912 21,202,783 21,477,631 21,479,986 Book value per common share - GAAP $ 16.72 $ 16.60 $ 16.05 $ 15.64 $ 15.47 Tangible book value 15.74 15.62 15.11 14.72 14.54 Tangible common equity to tangible assets reconciliation Total shareholders’ equity $ 340,328 $ 338,586 $ 340,309 $ 335,980 $ 332,300 Intangible assets (19,925) (19,925) (19,925) (19,925) (19,925) Total tangible common equity $ 320,403 $ 318,661 $ 320,384 $ 316,055 $ 312,375 Total assets $ 3,732,668 $ 3,615,617 $ 2,923,977 $ 2,890,622 $ 2,719,658 Intangible assets (19,925) (19,925) (19,925) (19,925) (19,925) Total tangible assets $ 3,712,743 $ 3,595,692 $ 2,904,052 $ 2,870,697 $ 2,699,733 Tangible common equity to tangible assets 8.63 % 8.86 % 11.03 % 11.01 % 11.57 % Allowance for credit losses to loans held for investment reconciliation Total loans held for investment $ 2,300,814 $ 2,249,036 $ 2,188,035 $ 2,184,694 $ 1,932,909 PPP loans (218,766) (192,160) (231,834) (234,049) — Total loans held for investment excluding PPP loans $ 2,082,048 $ 2,056,876 $ 1,956,201 $ 1,950,645 $ 1,932,909 Allowance for credit losses to loans held for investment 1.31 % 1.55 % 1.59 % 1.61 % 1.43 % Allowance for credit losses to loans held for investment excluding PPP loans 1.45 % 1.70 % 1.78 % 1.80 % 1.43 % First Quarter Third Quarter Second Quarter First Quarter 2021 2020 Fourth Quarter 11