Exhibit 99.1 PRESS RELEASE ATLANTIC CAPITAL BANCSHARES, INC. REPORTS SECOND QUARTER 2021 RESULTS Atlanta, GA – July 23, 2021 – Atlantic Capital Bancshares, Inc. (NASDAQ: ACBI) announced net income for the quarter ended June 30, 2021 of $11.8 million, or $0.58 per diluted share, compared to $1.8 million, or $0.09 per diluted share, for the second quarter of 2020 and $13.4 million, or $0.65 per diluted share, for the first quarter of 2021. “Atlantic Capital recorded another quarter of strong and sustainable growth in loans, deposits, and revenue. Our new business pipelines remain robust, our banking teams are executing at a high level, and we expect solid growth through the balance of 2021 and into 2022,” remarked Douglas Williams, President and Chief Executive Officer. Second Quarter Highlights(1) • Total assets were $3.8 billion, compared to $3.7 billion at March 31, 2021 and $2.9 billion at June 30, 2020. • Loans held for investment, excluding Paycheck Protection Program (“PPP”) loans, increased $77.2 million, or 15% annualized, from March 31, 2021 and increased $208.6 million, or 11%, from June 30, 2020. • Quarterly average deposits increased $150.7 million, or 19% annualized, compared to the first quarter of 2021 and increased $897.6 million, or 37%, compared to the second quarter of 2020. • Cost of deposits decreased to 0.10% from 0.12% in the first quarter of 2021 and from 0.22% in the second quarter of 2020. • Tangible book value per common share increased to $16.40 from $15.74 at March 31, 2021 and from $14.72 at June 30, 2020. • Annualized net charge-offs to average loans totaled 0.10% for the second quarter of 2021 and 0.07% for the full year 2021. Non-performing assets to total assets were 0.14% at June 30, 2021. • The allowance for credit losses was 1.27% of total loans held for investment at June 30, 2021, compared to 1.31% at March 31, 2021 and 1.61% at June 30, 2020. • 50,000 shares were repurchased in the second quarter of 2021 totaling $1.3 million at an average price of $25.71. As of June 30, 2021, approximately $1.8 million remained from our $25 million share repurchase program. Income Statement Taxable equivalent net interest income totaled $26.0 million for the second quarter of 2021, an increase of $4.1 million, or 18%, from the second quarter of 2020, and an increase of $2.3 million, or 39% annualized, from the first quarter of 2021. The second quarter of 2021 included $3.0 million in PPP loan income compared to $696,000 in the second quarter of 2020 and $2.2 million in the first quarter of 2021. The second quarter of 2021 also included $671,000 in interest income related to the receipt of an investment prepayment penalty and the accelerated accretion of a loan discount upon payoff. (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 13.

Taxable equivalent net interest margin was 2.91% in the second quarter of 2021, compared to 3.23% in the second quarter of 2020 and 2.81% in the first quarter of 2021. The tax equivalent net interest margin excluding PPP loans was 2.70%, unchanged from the first quarter of 2021. The yield on loans in the second quarter of 2021 was 4.19%, an increase of 32 basis points from the second quarter of 2020 and an increase of 30 basis points from the first quarter of 2021. Excluding PPP loans, the second quarter of 2021 loan yield was 3.95%, an increase of 12 basis points compared to the first quarter of 2021. In addition, loan interest income for the second quarter of 2021 included $405,000 in previously mentioned accelerated discount accretion. The cost of deposits in the second quarter of 2021 was 0.10%, a decrease of 12 basis points from the second quarter of 2020 and a decrease of 2 basis points from the first quarter of 2021. The cost of interest bearing deposits decreased 16 basis points to 0.17% from the second quarter of 2020, and decreased 2 basis points from the first quarter of 2021. In the second quarter of 2021, we recorded a negative provision for credit losses of $933,000 compared to a provision for credit losses of $8.9 million in the second quarter of 2020 and a negative provision for credit losses of $4.5 million in the first quarter of 2021. The second quarter of 2021 provision for credit losses included a negative provision for loan losses of $814,000 and a negative provision for unfunded commitments of $118,000. Noninterest income totaled $3.6 million in the second quarter of 2021 compared to $2.3 million in the second quarter of 2020 and unchanged from the first quarter of 2021. Service charge income in the second quarter of 2021 totaled $1.7 million, an increase of $646,000 compared to the second quarter of 2020, and an increase of $64,000 from the first quarter of 2021. The increase in service charge income was primarily due to growth in our payments and fintech businesses. Noninterest expense totaled $15.2 million in the second quarter of 2021, compared to $12.9 million in the second quarter of 2020 and $15.1 million in the first quarter of 2021. Salaries and employee benefits expense totaled $10.4 million in the second quarter of 2021, unchanged compared to the first quarter of 2021. Balance Sheet Total loans held for investment were $2.3 billion at June 30, 2021, an increase of $80.2 million from June 30, 2020 and a decrease of $35.9 million from March 31, 2021. Loans held for investment, excluding PPP loans, increased $77.2 million, or 15% annualized, from March 31, 2021 and increased $208.6 million, or 11%, from June 30, 2020. The allowance for credit losses was 1.27% of total loans held for investment at June 30, 2021, compared to 1.31% at March 31, 2021. The decrease in the allowance was a result of an improvement in our current expected credit losses, or CECL, economic forecast along with credit rating upgrades for certain criticized and classified loans. Excluding the impact of PPP loans, the allowance for credit losses at June 30, 2021 was 1.33%, compared to 1.45% at March 31, 2021. Total average deposits were $3.3 billion for the second quarter of 2021, an increase of $897.6 million, or 37%, from the second quarter of 2020 and an increase of $150.7 million, or 19% annualized, from the first quarter of 2021. Average noninterest bearing deposits were $1.3 billion for the second quarter of 2021, an increase of $480.4 million, or 59%, from the second quarter of 2020 and an increase of $159.2 million, or 56% annualized, from the first quarter of 2021. Noninterest bearing deposits were 39.2% of total average deposits in the second quarter of 2021, compared to 33.8% in the second quarter of 2020 and 36.0% in the first quarter of 2021. 2

Subsequent Event As announced and further described in a separate press release issued by Atlantic Capital today, Atlantic Capital and South State Corporation, have entered into a merger agreement under which South State will acquire Atlantic Capital in an all stock merger transaction. Conference Call In light of the announcement earlier today of our entry into a merger agreement with South State Corporation, Atlantic Capital and South State will host a joint conference call at 8:00 a.m. ET on Friday, July 23, 2021, to discuss the transaction and the financial results for the quarter ended June 30, 2021. Individuals wishing to participate in the conference call may do so by dialing 1-877-506-9272 from the United States. The call will also be available live via webcast at https://services.choruscall.com/links/ssb210723.html. Non-GAAP Financial Measures 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) loans held for investment excluding PPP loans (iv) loan yield excluding PPP loans; (v) taxable equivalent net interest margin; (vi) taxable equivalent net interest margin excluding PPP loans; (vii) taxable equivalent income before income taxes; (viii) taxable equivalent income tax expense; (ix) tangible common equity to tangible assets; (x) tangible book value per common share, and (xi) 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 identified 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 3

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 $3.8 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: Ashley Carson Email: [email protected] Phone: 404-995-6050 (ACB-ER) Financial Contact: Patrick Oakes Email: [email protected] Phone: 404-995-6050 4

ATLANTIC CAPITAL BANCSHARES, INC. Selected Financial Information (in thousands, except share and per share data; taxable equivalent) INCOME SUMMARY Interest income - taxable equivalent (1) $ 27,993 $ 25,775 $ 25,288 $ 24,578 $ 24,151 $ 53,768 $ 50,397 Interest expense 1,958 2,065 2,299 2,515 2,166 4,023 7,209 Net interest income - taxable equivalent 26,035 23,710 22,989 22,063 21,985 49,745 43,188 Provision for credit losses (933) (4,519) 481 28 8,863 (5,452) 16,937 Net interest income after provision for credit losses 26,968 28,229 22,508 22,035 13,122 55,197 26,251 Noninterest income 3,584 3,562 3,016 2,504 2,343 7,146 4,765 Noninterest expense 15,197 15,149 13,164 13,713 12,904 30,346 25,781 Income before income taxes 15,355 16,642 12,360 10,826 2,561 31,997 5,235 Income tax expense 3,539 3,280 2,410 2,208 712 6,819 1,262 Net income(1)(2) $ 11,816 $ 13,362 $ 9,950 $ 8,618 $ 1,849 $ 25,178 $ 3,973 PER SHARE DATA Diluted earnings per share $ 0.58 $ 0.65 $ 0.48 $ 0.40 $ 0.09 $ 1.23 $ 0.18 Book value per share 17.38 16.72 16.60 16.05 15.64 17.38 15.64 Tangible book value per common share (2) 16.40 15.74 15.62 15.11 14.72 16.40 14.72 PERFORMANCE MEASURES Return on average equity 13.60 % 15.99 % 11.68 % 10.05 % 2.20 % 14.77 % 2.38 % Return on average assets 1.26 1.50 1.19 1.15 0.25 1.38 0.28 Taxable equivalent net interest margin 2.91 2.81 2.91 3.14 3.23 2.86 3.32 Taxable equivalent net interest margin excluding PPP loans 2.70 2.70 2.81 3.18 3.35 2.70 3.38 Efficiency ratio 51.97 56.30 51.30 56.61 53.82 54.04 54.42 Average loans to average deposits 67.54 71.93 76.81 88.65 88.46 69.67 86.23 CAPITAL Average equity to average assets 9.24 % 9.39 % 10.18 % 11.45 % 11.53 % 9.31 % 11.95 % Tangible common equity to tangible assets 8.86 8.63 8.86 11.03 11.01 8.86 11.01 Leverage ratio 8.4 (3) 8.4 8.9 9.9 9.9 8.5 (4) 10.3 Total risk based capital ratio 16.0 (3) 16.4 16.1 16.9 14.8 16.0 (4) 14.8 SHARES OUTSTANDING Number of common shares outstanding - basic 20,319,429 20,354,077 20,394,912 21,202,783 21,477,631 20,319,429 21,477,631 Number of common shares outstanding - diluted 20,595,812 20,617,188 20,492,542 21,298,098 21,569,050 20,595,812 21,569,050 Average number of common shares - basic 20,332,503 20,380,066 20,711,089 21,500,735 21,472,462 20,356,153 21,580,855 Average number of common shares - diluted 20,516,478 20,502,184 20,795,332 21,543,805 21,535,040 20,509,370 21,688,712 ASSET QUALITY Allowance for credit losses to loans held for investment 1.27 % 1.31 % 1.55 % 1.59 % 1.61 % 1.27 % 1.61 % Net charge-offs to average loans (4) 0.10 0.04 0.05 0.06 0.29 0.07 0.17 Non-performing assets to total assets 0.14 0.06 0.13 0.20 0.24 0.14 0.24 AVERAGE BALANCES Total loans $ 2,233,906 $ 2,270,660 $ 2,207,956 $ 2,191,669 $ 2,131,847 $ 2,252,182 $ 2,011,016 Investment securities 656,507 579,547 491,134 453,382 462,850 618,239 440,410 Total assets 3,771,970 3,611,417 3,328,719 2,977,444 2,932,716 3,692,133 2,809,491 Deposits 3,307,601 3,156,906 2,874,402 2,472,218 2,409,958 3,232,669 2,332,231 Shareholders' equity 348,416 338,990 338,948 341,017 338,027 343,725 335,754 AT PERIOD END Loans and loans held for sale $ 2,264,899 $ 2,302,661 $ 2,249,036 $ 2,188,894 $ 2,185,847 $ 2,264,899 $ 2,185,847 Investment securities 714,065 613,236 535,579 446,706 457,749 714,065 457,749 Total assets 3,780,445 3,732,668 3,615,617 2,923,977 2,890,622 3,780,445 2,890,622 Deposits 3,306,224 3,277,692 3,161,508 2,468,722 2,407,631 3,306,224 2,407,631 Shareholders’ equity 353,185 340,328 338,586 340,309 335,980 353,185 335,980 (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 June 30, 2021. (4)Annualized. Quarter Fourth Quarter Second 2020 2021 First Third Quarter Quarter For the six months ended 2021 2020 Quarter June 30, Second 5

face="Arial" style="color:white;font-size:1.0pt;">ATLANTIC CAPITAL BANCSHARES, INC. 35,530 $ 32,850 $ 16,865 $ 33,759 593,195 612,966 636,537 33,038 628,725 645,816 653,402 66,797 available for sale 480,518 390,701 335,423 271,829 held to maturity, net of allowance for credit losses of $13 at June 30, 2021, March 31, 2021, December 31, 233,547 222,535 200,156 185,920 24,293 24,709 25,892 28,811 — 1,847 — 1,153 2,300,814 2,249,036 2,184,694 (26,123) (27,506) (31,818) (31,605) 2,238,776 2,273,308 2,217,218 2,153,089 19,643 20,633 21,589 22,494 73,610 73,223 72,856 67,127 19,925 19,925 19,925 2,637 2,688 2,731 2,731 16 16 16 779 57,267 66,409 69,967 $ 3,732,668 $ 3,615,617 $ 2,890,622 EQUITY $ 1,280,524 $ 1,033,765 $ 883,662 536,677 485,540 760,638 449,737 562 625 583 1,142,361 1,030,753 879,863 294,129 241,328 131,353 84,958 74,576 94,399 62,433 3,277,692 3,161,508 2,407,631 — — — 6,000 — — — 50,000 73,878 73,807 49,958 47,083 40,770 41,716 41,053 3,392,340 3,277,031 2,554,642 par value; 10,000,000 shares authorized; no shares as of June 30, 2021, March 31, 2021, and June 30, 2020 — — — — value; 100,000,000 shares authorized; 20,319,429, and 21,477,631 shares issued and outstanding as of 31, 2021, December 31, 2020 and June 30, 2020, 207,047 209,942 224,520 139,315 127,499 114,137 95,570 comprehensive income 7,251 5,782 14,507 15,890 equity 353,185 340,328 338,586 335,980 AND SHAREHOLDERS’ EQUITY $ 3,780,445 $ 3,732,668 $ 3,615,617 $ 2,890,622

ATLANTIC CAPITAL BANCSHARES, INC. Consolidated Statements of Income (unaudited) (in thousands, except share and per share data) INTEREST INCOME Loans, including fees $ 23,352 $ 21,769 $ 21,609 $ 21,049 $ 20,496 $ 45,121 $ 42,922 Investment securities 3,900 3,374 3,000 2,910 3,041 7,274 5,773 Interest and dividends on other interest‑earning assets 366 267 334 274 260 633 1,125 Total interest income 27,618 25,410 24,943 24,233 23,797 53,028 49,820 INTEREST EXPENSE Interest on deposits 851 971 1,188 1,151 1,299 1,822 5,481 Interest on Federal Home Loan Bank advances — — — 16 38 — 38 Interest on federal funds purchased and securities sold under agreements to repurchase — — — 3 6 — 38 Interest on long-term debt 1,107 1,094 1,111 1,345 823 2,201 1,652 Total interest expense 1,958 2,065 2,299 2,515 2,166 4,023 7,209 NET INTEREST INCOME BEFORE PROVISION FOR CREDIT LOSSES 25,660 23,345 22,644 21,718 21,631 49,005 42,611 Provision for credit losses (933) (4,519) 481 28 8,863 (5,452) 16,937 NET INTEREST INCOME AFTER PROVISION FOR CREDIT LOSSES 26,593 27,864 22,163 21,690 12,768 54,457 25,674 NONINTEREST INCOME Service charges 1,727 1,663 1,341 1,217 1,081 3,390 2,313 Gains (losses) on sale of securities — 2 (23) — — 2 — (Losses) gains on sale of other assets — — (6) (145) — — 5 Derivatives (loss) income (7) 47 11 10 (10) 40 236 Bank owned life insurance 388 391 368 363 367 779 729 SBA lending activities 1,231 1,225 1,015 893 782 2,456 1,196 Other noninterest income 245 234 310 166 123 479 286 Total noninterest income 3,584 3,562 3,016 2,504 2,343 7,146 4,765 NONINTEREST EXPENSE Salaries and employee benefits 10,362 10,421 8,437 8,850 8,466 20,783 16,942 Occupancy 778 734 767 739 883 1,512 1,677 Equipment and software 819 774 969 826 763 1,593 1,542 Professional services 723 922 686 562 792 1,645 1,497 Communications and data processing 869 792 789 757 670 1,661 1,567 Marketing and business development 138 108 144 141 79 246 232 Travel, meals and entertainment 47 10 14 39 34 57 174 FDIC premiums 421 275 241 213 175 696 175 Other noninterest expense 1,040 1,113 1,117 1,586 1,042 2,153 1,975 Total noninterest expense 15,197 15,149 13,164 13,713 12,904 30,346 25,781 INCOME BEFORE PROVISION FOR INCOME TAXES 14,980 16,277 12,015 10,481 2,207 31,257 4,658 Provision for income taxes 3,164 2,915 2,065 1,863 358 6,079 685 NET INCOME $ 11,816 $ 13,362 $ 9,950 $ 8,618 $ 1,849 $ 25,178 $ 3,973 Net income per common share - basic $ 0.58 $ 0.66 $ 0.48 $ 0.40 $ 0.09 $ 1.24 $ 0.18 Net income per common share - diluted $ 0.58 $ 0.65 $ 0.48 $ 0.40 $ 0.09 $ 1.23 $ 0.18 Weighted average shares - basic 20,332,503 20,380,066 20,711,089 21,500,735 21,472,462 20,356,153 21,580,855 Weighted average shares - diluted 20,516,478 20,502,184 20,795,332 21,543,805 21,535,040 20,509,370 21,688,712 March 31, 2021 June 30, 2020 Six months ended Three months ended 2020 June 30, 2021 June 30, 2021 December 31, 2020 June 30, 2020 September 30, 7

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 $ 687,795 $ 201 0.12 % $ 561,809 $ 168 0.12 % Investment securities Taxable investment securities 426,634 2,382 2.24 356,250 1,898 2.16 Non-taxable investment securities (1) 229,873 1,893 3.30 223,297 1,841 3.34 Total investment securities 656,507 4,275 2.61 579,547 3,739 2.62 Loans 2,233,906 23,352 4.19 2,270,660 21,769 3.89 FHLB and FRB stock 11,931 165 5.55 12,701 99 3.17 Total interest-earning assets 3,590,139 27,993 3.13 3,424,717 25,775 3.05 Non-earning assets 181,831 186,700 Total assets $ 3,771,970 $ 3,611,417 Liabilities Interest bearing deposits: NOW, money market, and saving 1,637,374 725 0.18 1,662,097 834 0.20 Time deposits 290,331 68 0.09 273,615 74 0.11 Brokered deposits 84,168 58 0.28 84,663 63 0.30 Total interest-bearing deposits 2,011,873 851 0.17 2,020,375 971 0.19 Total borrowings 89 — — — — — Total long-term debt 73,904 1,107 6.01 73,830 1,094 6.01 Total interest-bearing liabilities 2,085,866 1,958 0.38 2,094,205 2,065 0.40 Demand deposits 1,295,728 1,136,531 Other liabilities 41,960 41,691 Shareholders’ equity 348,416 338,990 Total liabilities and shareholders’ equity $ 3,771,970 $ 3,611,417 Net interest spread 2.75 % 2.65 % Net interest income and net interest margin (2) $26,035 2.91 % $ 23,710 2.81 % Non-taxable equivalent net interest margin 2.87 % 2.76 % 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 $ 687,795 $ 201 0.12 % $ 129,989 $ 23 0.07 % Investment securities Taxable investment securities 426,634 2,382 2.24 247,668 1,581 2.57 Non-taxable investment securities (1) 229,873 1,893 3.30 215,182 1,814 3.39 Total investment securities 656,507 4,275 2.61 462,850 3,395 2.95 Loans 2,233,906 23,352 4.19 2,131,847 20,496 3.87 FHLB and FRB stock 11,931 165 5.55 16,842 237 5.66 Total interest-earning assets 3,590,139 27,993 3.13 2,741,528 24,151 3.54 Non-earning assets 181,831 191,188 Total assets $ 3,771,970 $ 2,932,716 Liabilities Interest bearing deposits: NOW, money market, and saving 1,637,374 725 0.18 1,415,069 1,115 0.32 Time deposits 290,331 68 0.09 96,362 58 0.24 Brokered deposits 84,168 58 0.28 83,228 126 0.61 Total interest-bearing deposits 2,011,873 851 0.17 1,594,659 1,299 0.33 Total borrowings 89 — — 97,769 44 0.18 Total long-term debt 73,904 1,107 6.01 49,930 823 6.63 Total interest-bearing liabilities 2,085,866 1,958 0.38 1,742,358 2,166 0.50 Demand deposits 1,295,728 815,299 Other liabilities 41,960 37,032 Shareholders’ equity 348,416 338,027 Total liabilities and shareholders’ equity $ 3,771,970 $ 2,932,716 Net interest spread 2.75 % 3.04 % Net interest income and net interest margin (2) $26,035 2.91 % $ 21,985 3.23 % Non-taxable equivalent net interest margin 2.87 % 3.17 % (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. Balance Three months ended March 31, 2021 Interest Income/ Expense Interest Income/ Expense June 30, 2021 Average Balance Average Balance Interest Income/ Expense Three months ended June 30, 2021 June 30, 2020 Interest Income/ Expense Average Balance Average 8

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) $ (1,153) Total loans held for sale $— $ 1,847 $ — $ 859 $ 1,153 $ (1,847) $ (1,153) Loans held for investment Commercial loans: Commercial and industrial - other $ 767,646 $ 735,287 $ 760,645 $ 712,567 $ 739,769 $ 32,359 $ 27,877 Commercial and industrial - PPP 105,684 218,766 192,160 231,834 234,049 (113,082) (128,365) Commercial real estate: Multifamily 58,632 80,507 66,262 58,336 58,909 (21,875) (277) Owner occupied 392,108 381,018 373,689 364,170 366,847 11,090 25,261 Investment 506,230 480,566 469,150 458,279 474,565 25,664 31,665 Construction and land: 1‑4 family residential construction 2,074 1,578 1,171 — 11 496 2,063 Other construction, development, and land 178,423 141,218 144,424 139,836 128,980 37,205 49,443 Total commercial loans 2,010,797 2,038,940 2,007,501 1,965,022 2,003,130 (28,143) 7,667 Residential: Residential mortgages 45,207 31,817 33,783 29,460 32,327 13,390 12,880 Home equity 24,972 26,293 25,443 24,528 23,689 (1,321) 1,283 Total residential loans 70,179 58,110 59,226 53,988 56,016 12,069 14,163 Consumer 184,203 203,176 176,066 154,916 113,149 (18,973) 71,054 Other 5,234 7,689 13,897 22,777 22,160 (2,455) (16,926) 2,270,413 2,307,915 2,256,690 2,196,703 2,194,455 (37,502) 75,958 Less net deferred fees and other unearned income (5,514) (7,101) (7,654) (8,668) (9,761) 1,587 4,247 Total loans held for investment $ 2,264,899 $ 2,300,814 $ 2,249,036 $ 2,188,035 $ 2,184,694 $ (35,915) $ 80,205 Total loans $ 2,264,899 $ 2,302,661 $ 2,249,036 $ 2,188,894 $ 2,185,847 $ (37,762) $ 79,052 Total unfunded commitments $ 804,784 $ 789,869 $ 813,757 $ 764,247 $ 749,321 $ 14,915 $ 55,463 June 30, 2021 December 31, 2020 September 30, 2020 March 31, 2021 Year Over Year Change 2020 Linked Quarter Change June 30, 10

ATLANTIC CAPITAL BANCSHARES, INC. Allowance for Credit Losses Activity and Credit Quality (dollars in thousands) Allowance for loan losses Balance at beginning of period $ 27,506 $ 31,818 $ 31,894 $ 31,605 $ 24,896 Provision for loan losses (814) (4,074) 225 636 8,222 Loans charged-off: Commercial and industrial (386) (288) (401) (404) (1,479) Commercial real estate — — — — — Construction and land — — — — — Residential mortgages (223) — — — (36) Home equity — — — — — Consumer — — — — — Other — — — — — Total loans charged-off (609) (288) (401) (404) (1,515) Recoveries on loans previously charged-off: Commercial and industrial 6 50 37 56 1 Commercial real estate — — 44 — — Construction and land — — 18 — — Residential mortgages 32 — — — — Home equity — — — — — Consumer 2 — 1 1 1 Other — — — — — Total recoveries 40 50 100 57 2 Net charge-offs $ (569) $ (238) $ (301) $ (347) $ (1,513) Balance at period end $ 26,123 $ 27,506 $ 31,818 $ 31,894 $ 31,605 Allowance for unfunded commitments Balance at beginning of period $ 2,683 $ 3,128 $ 2,871 $ 3,480 $ 2,838 Provision for unfunded commitments (118) (445) 257 (609) 642 Balance at period end $ 2,565 $ 2,683 $ 3,128 $ 2,871 $ 3,480 Total allowance for credit losses - loans and unfunded commitments $ 28,688 $ 30,189 $ 34,946 $ 34,765 $ 35,085 Provision for credit losses under CECL Provision for loan losses (814) (4,074) 225 636 8,222 Provision for securities held to maturity credit losses (1) - (1) 1 (1) Provision for unfunded commitments (118) (445) 257 (609) 642 Total provision for credit losses $ (933) $ (4,519) $ 481 $ 28 $ 8,863 Non-performing loans $ 5,194 $ 2,056 $ 4,862 $ 5,421 $ 6,265 Foreclosed properties (OREO) 16 16 16 563 779 Total nonperforming assets $ 5,210 $ 2,072 $ 4,878 $ 5,984 $ 7,044 Allowance for loan losses to loans held for investment 1.15 % 1.20 % 1.41 % 1.46 % 1.45 % Allowance for credit losses to loans held for investment 1.27 % 1.31 % 1.55 % 1.59 % 1.61 % Allowance for credit losses to loans held for investment excluding PPP loans 1.33 % 1.45 % 1.70 % 1.78 % 1.80 % Net charge-offs to average loans (1) 0.10 0.04 0.05 0.06 0.29 Non-performing loans as a percentage of total loans 0.23 % 0.09 % 0.22 % 0.25 % 0.29 % Non-performing assets as a percentage of total assets 0.14 % 0.06 % 0.13 % 0.20 % 0.24 % (1)Annualized. 2021 Second Quarter First Quarter Quarter Second 2020 Fourth Quarter Third Quarter 11

ATLANTIC CAPITAL BANCSHARES, INC. Period End Deposits (dollars in thousands) DDA $ 1,374,018 $ 1,280,524 $ 1,033,765 $ 843,656 $ 883,662 $ 93,494 $ 490,356 NOW 536,677 485,540 760,638 387,858 449,737 51,137 86,940 Savings 676 562 625 568 583 114 93 Money market 1,026,239 1,142,361 1,030,753 945,834 879,863 (116,122) 146,376 Time 283,656 294,129 241,328 196,343 131,353 (10,473) 152,303 Brokered 84,958 74,576 94,399 94,463 62,433 10,382 22,525 Total deposits $ 3,306,224 $ 3,277,692 $ 3,161,508 $ 2,468,722 $ 2,407,631 $ 28,532 $ 898,593 Average Deposits (dollars in thousands) DDA $ 1,295,728 $ 1,136,531 $ 977,009 $ 854,715 $ 815,299 $ 159,197 $ 480,429 NOW 548,358 618,701 558,967 440,734 462,051 (70,343) 86,307 Savings 593 587 614 586 574 6 19 Money market 1,088,423 1,042,809 1,026,347 942,062 952,444 45,614 135,979 Time 290,331 273,615 221,792 166,019 96,362 16,716 193,969 Brokered 84,168 84,663 89,673 68,102 83,228 (495) 940 Total deposits $ 3,307,601 $ 3,156,906 $ 2,874,402 $ 2,472,218 $ 2,409,958 $ 150,695 $ 897,643 Noninterest bearing deposits as a percentage of average deposits 39.2 % 36.0 % 34.0 % 34.6 % 33.8 % Cost of interest-bearing deposits 0.17 % 0.19 % 0.25 % 0.28 % 0.33 % Cost of deposits 0.10 % 0.12 % 0.16 % 0.19 % 0.22 % Linked Quarter Change June 30, 2021 Year Over Year Change 2021 March 31, September 30, 2020 2020 June 30, December 31, 2020 Linked 2021 2020 Quarter Q2 2021 vs Second First Fourth Third Second Change Q2 2020 Quarter Quarter Quarter Quarter Quarter 12

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 $ 27,618 $ 25,410 $ 24,943 $ 24,233 $ 23,797 $ 53,028 $ 49,820 Taxable equivalent adjustment 375 365 345 345 354 740 577 Interest income - taxable equivalent $ 27,993 $ 25,775 $ 25,288 $ 24,578 $ 24,151 $ 53,768 $ 50,397 Taxable equivalent net interest income reconciliation Net interest income - GAAP $ 25,660 $ 23,345 $ 22,644 $ 21,718 $ 21,631 $ 49,005 $ 42,611 Taxable equivalent adjustment 375 365 345 345 354 740 577 Net interest income - taxable equivalent $ 26,035 $ 23,710 $ 22,989 $ 22,063 $ 21,985 $ 49,745 $ 43,188 Loan yield excluding PPP loans reconciliation Loan yield - GAAP 4.19 % 3.89 % 3.89 % 3.82 % 3.87 % 4.04 % 4.29 % Impact of PPP loans (0.24) (0.06) (0.03) 0.13 0.22 (0.15) 0.14 Loan yield excluding PPP loans 3.95 % 3.83 % 3.86 % 3.95 % 4.09 % 3.89 % 4.43 % Taxable equivalent net interest margin reconciliation Net interest margin - GAAP 2.87 % 2.76 % 2.86 % 3.09 % 3.17 % 2.82 % 3.27 % Impact of taxable equivalent adjustment 0.04 0.05 0.05 0.05 0.06 0.04 0.05 Net interest margin - taxable equivalent 2.91 % 2.81 % 2.91 % 3.14 % 3.23 % 2.86 % 3.32 % Taxable equivalent net interest margin excluding PPP loans reconciliation Net interest margin - taxable equivalent 2.91 % 2.81 % 2.91 % 3.14 % 3.23 % 2.86 % 3.32 % Impact of PPP loans (0.21) (0.11) (0.10) 0.04 0.12 (0.16) 0.06 Net interest margin - taxable equivalent excluding PPP loans 2.70 % 2.70 % 2.81 % 3.18 % 3.35 % 2.70 % 3.38 % Taxable equivalent income before income taxes reconciliation Income before income taxes - GAAP $ 14,980 $ 16,277 $ 12,015 $ 10,481 $ 2,207 $ 31,257 $ 4,658 Taxable equivalent adjustment 375 365 345 345 354 740 577 Income before income taxes $ 15,355 $ 16,642 $ 12,360 $ 10,826 $ 2,561 $ 31,997 $ 5,235 Taxable equivalent income tax expense reconciliation Income tax expense - GAAP $ 3,164 $ 2,915 $ 2,065 $ 1,863 $ 358 $ 6,079 $ 685 Taxable equivalent adjustment 375 365 345 345 354 740 577 Income tax expense $ 3,539 $ 3,280 $ 2,410 $ 2,208 $ 712 $ 6,819 $ 1,262 Tangible book value per common share reconciliation Total shareholders’ equity $ 353,185 $ 340,328 $ 338,586 $ 340,309 $ 335,980 $ 353,185 $ 335,980 Intangible assets (19,925) (19,925) (19,925) (19,925) (19,925) (19,925) (19,925) Total tangible common equity $ 333,260 $ 320,403 $ 318,661 $ 320,384 $ 316,055 $ 333,260 $ 316,055 Common shares outstanding 20,319,429 20,354,077 20,394,912 21,202,783 21,477,631 20,319,429 21,477,631 Book value per common share - GAAP $ 17.38 $ 16.72 $ 16.60 $ 16.05 $ 15.64 $ 17.38 $ 15.64 Tangible book value 16.40 15.74 15.62 15.11 14.72 16.40 14.72 Tangible common equity to tangible assets reconciliation Total shareholders’ equity $ 353,185 $ 340,328 $ 338,586 $ 340,309 $ 335,980 $ 353,185 $ 335,980 Intangible assets (19,925) (19,925) (19,925) (19,925) (19,925) (19,925) (19,925) Total tangible common equity $ 333,260 $ 320,403 $ 318,661 $ 320,384 $ 316,055 $ 333,260 $ 316,055 Total assets $ 3,780,445 $ 3,732,668 $ 3,615,617 $ 2,923,977 $ 2,890,622 $ 3,780,445 $ 2,890,622 Intangible assets (19,925) (19,925) (19,925) (19,925) (19,925) (19,925) (19,925) Total tangible assets $ 3,760,520 $ 3,712,743 $ 3,595,692 $ 2,904,052 $ 2,870,697 $ 3,760,520 $ 2,870,697 Tangible common equity to tangible assets 8.86 % 8.63 % 8.86 % 11.03 % 11.01 % 8.86 % 11.01 % Allowance for credit losses to loans held for investment reconciliation Total loans held for investment $ 2,264,899 $ 2,300,814 $ 2,249,036 $ 2,188,035 $ 2,184,694 $ 2,264,899 $ 2,184,694 PPP loans (105,684) (218,766) (192,160) (231,834) (234,049) (105,684) (234,049) Total loans held for investment excluding PPP loans $ 2,159,215 $ 2,082,048 $ 2,056,876 $ 1,956,201 $ 1,950,645 $ 2,159,215 $ 1,950,645 Allowance for credit losses to loans held for investment 1.27 % 1.31 % 1.55 % 1.59 % 1.61 % 1.27 % 1.61 % Allowance for credit losses to loans held for investment excluding PPP loans 1.33 % 1.45 % 1.70 % 1.78 % 1.80 % 1.33 % 1.80 % For the six months ended June 30, 2021 2020 Second Quarter Fourth Quarter Third Quarter Second Quarter First Quarter 2021 2020 13