Southside Bancshares : Gulf South Bank Conference

NASDAQ: SBSI

Gulf South Bank Conference

May 8, 2023

Forward-Looking Statements

• Certain statements of other than historical fact that are contained in this press release and in other written materials, documents and oral statements issued by or on behalf of the Company may be considered to be "forward-looking statements" within the meaning of and subject to the safe harbor protections of the Private Securities Litigation Reform Act of 1995. These forward- looking statements are not guarantees of future performance, nor should they be relied upon as representing management's views as of any subsequent date. These statements may include words such as "expect," "estimate," "project," "anticipate," "appear," "believe," "could," "should," "may," "might," "will," "would," "seek," "intend," "probability," "risk," "goal," "target," "objective," "plans," "potential," and similar expressions. Forward-looking statements are statements with respect to the Company's beliefs, plans, expectations, objectives, goals, anticipations, assumptions, estimates, intentions and future performance and are subject to significant known and unknown risks and uncertainties, which could cause the Company's actual results to differ materially from the results discussed in the forward-looking statements. For example, discussions of the effect of our expansion, benefits of the Share Repurchase Plan, trends in asset quality, capital, liquidity, the Company's ability to sell nonperforming assets, expense reductions, planned operational efficiencies and earnings from growth and certain market risk disclosures, including the impact of interest rates, tax reform, inflation, the impacts related to or resulting from Russia's invasion of Ukraine and other economic factors are based upon information presently available to management and are dependent on choices about key model characteristics and assumptions and are subject to various limitations. By their nature, certain of the market risk disclosures are only estimates and could be materially different from what actually occurs in the future. Accordingly, our results could materially differ from those that have been estimated. The most significant factor that could cause future results to differ materially from those anticipated by our forward-looking statements include the ongoing impact of higher inflation levels, higher interest rates and general economic and recessionary concerns, all of which could impact economic growth and could cause a reduction in financial transactions and business activities, including decreased deposits and reduced loan originations, our ability to manage liquidity in a rapidly changing and unpredictable market, supply chain disruptions, labor shortages and additional interest rate increases by the Federal Reserve.
• Additional information concerning the Company and its business, including additional factors that could materially affect the Company's financial results, is included in the Company's Annual Report on Form 10-K for the year ended December 31, 2022, under "Part I - Item 1. Forward Looking Information" and in the Company's other filings with the Securities and Exchange Commission. The Company disclaims any obligation to update any factors or to announce publicly the result of revisions to any of the forward-looking statements included herein to reflect future events or developments.

2

Key Management Team

Lee Gibson, President & Chief Executive Officer

• Board and Executive Committee member of Tyler Economic Development Council
• Board member Texas Bankers Association
• Past Chairman, FHLB Dallas and Council of FHLBanks
• 38 years with Southside

Julie Shamburger, Chief Financial Officer

• Chief Accounting Officer of Southside Bank from 2011-2016
• 40 years with Southside

Tim Alexander, Chief Lending Officer

• Trustee Board member of The Great Commission Foundation of Episcopal Diocese of Texas
• 17 years with Southside and over 36 years of experience in commercial lending

TL Arnold, Chief Credit Officer

• Board member of William Mann Community Development Corporation
• 8 years with Southside and over 35 years of experience in the banking and financial services industry

Brian McCabe, Chief Operations Officer

• Board member of East Texas Lighthouse for the Blind and CHRISTUS Trinity Mother Frances Foundation
• 39 years with Southside

Suni Davis, Chief Risk Officer

• Financial Managers Society Audit and Risk Council Member
• 23 years with Southside

3

Southside Snapshot

Company Overview

• Founded in 1960 with headquarters in Tyler, TX
• Community-focusedfinancial institution
• Offers a broad range of consumer, commercial and mortgage banking services, as well as private banking, wealth management and trust services, and brokerage services
• Recognized as a Top 25 Bank by Bank Director, based on 2021 financial performance
• Awarded one of the "Best Banks to Work For" in 2022 by American Banker
• Diversified branch footprint consisting of 55 branches, 13 of which are located in grocery stores
• 799 Full-Time Equivalent Employees
• Insider ownership equal to 5.43%(1)
• Experienced Management Team, each with over 20 years of experience in Banking
• Track record of consistent growth, 3.5% CAGR in total assets from 2018 - Q1 2023
• Strong asset quality, with NPA to Total Assets of 0.04%

Financial Highlights ($mm)

							As of and for the
		As of and for the Years Ended			Three Months
		December 31,			Ended March 31,
		2021			2022			2023
Balance Sheet	$	7,260	$	7,559	$	7,792
Total Assets
Total Loan (EX HFS)		3,645			4,148			4,153
Total Deposits		5,722			6,198			5,838
Total Equity		912			746			751
Profitability		1.59 %			1.43 %			1.38 %
ROAA
ROATCE(2)		17.04			18.56			19.36
Net Interest Margin(2)(3)		3.16			3.32			3.21
Efficiency Ratio(2)(3)		49.03			47.39			50.99
Capital		9.99 %			7.35 %			7.19 %
TCE/TA(2)
Common Equity Tier 1 Ratio		14.17			12.63			12.73
Tier 1 Risk-Based Ratio		15.43			13.70			13.81
Total Risk-Based Ratio		18.15			16.11			16.28
Leverage Ratio		10.33			9.96			9.83
Asset Quality		0.32 %			0.26 %			0.08 %
NPAs/Loans and Oreo
NCOs/Avg Loans		0.02			0.02			0.03
Reserve/ Total Loans		0.97			0.88			0.87
Reserve/NPLs		303.84			341.42			1,146.48
Per Common Share	$	21.77	$	17.13	$	17.54
Tangible Book Value(2)
Diluted Earnings		3.47			3.26			0.83

1. Source: Bloomberg as of 4/26/2023

(2)	See Non-GAAP Reconciliation	4
(3)	Calculated on a fully taxable-equivalent basis (FTE)

Markets of Operation

East Texas

Dallas - Fort Worth

Southeast Texas

Austin

Houston

• of
  Branches

25

15

11

2

2

Background and Highlights

• Founded in 1960 in Tyler, TX
• Leading deposit market share (38%) in Smith County
• Tyler metropolitan area population of approximately 235,000
• Acquired Fort Worth Bancshares, Inc. ($129m in Assets) in 2007 and OmniAmerican Bancorp, Inc. ($1.4b in Assets) in 2014
• #1 largest MSA in Texas and #4 in U.S.
• 24 Fortune 500 Companies
• Acquired Diboll State Bancshares, Inc. ($1.0b in Assets) in 2017
• Leading deposit market share (32%) in Angelina County
• Lufkin metropolitan area population of approximately 90,000
• Expanded footprint to Austin with LPO acquired through Fort Worth Bancshares, Inc. transaction in 2007, became a full service branch in 2011
• #4 largest MSA in Texas
• Fastest growing MSA in Texas, with a 34% increase in the last 10 years
• Expanded footprint to the Greater Houston Area in 2019 with an in- store branch in Kingwood
• #2 largest MSA in Texas and #5 in the US
• 22 Fortune 500 Companies

Source: FDIC (as of 6/30/2022), S&P Market Intelligence, Fortune Magazine

5