#1WA Western Alliance Bancorporation® INVESTOR UPDATE 1Q 2023#2Forward-Looking Statements This presentation contains forward-looking statements that relate to expectations, beliefs, projections, future plans and strategies, anticipated events or trends and similar expressions concerning matters that are not historical facts. Examples of forward-looking statements include, among others, statements we make regarding our expectations with regard to our business, financial and operating results, future economic performance and dividends. The forward-looking statements contained herein reflect our current views about future events and financial performance and are subject to risks, uncertainties, assumptions and changes in circumstances that may cause our actual results to differ significantly from historical results and those expressed in any forward-looking statement. Some factors that could cause actual results to differ materially from historical or expected results include, among others: the risk factors discussed in the Company's Annual Report on Form 10-K for the year ended December 31, 2021 and the Company's subsequent Quarterly Reports on Form 10-Q, each as filed with the Securities and Exchange Commission; the potential adverse effects of unusual and infrequently occurring events such as the COVID-19 pandemic and any governmental or societal responses thereto; changes in general economic conditions, either nationally or locally in the areas in which we conduct or will conduct our business; the impact on financial markets from geopolitical conflicts such as the war between Russia and Ukraine; inflation, interest rate, market and monetary fluctuations; increases in competitive pressures among financial institutions and businesses offering similar products and services; higher defaults on our loan portfolio than we expect; changes in management's estimate of the adequacy of the allowance for credit losses; legislative or regulatory changes or changes in accounting principles, policies or guidelines; supervisory actions by regulatory agencies which may limit our ability to pursue certain growth opportunities, including expansion through acquisitions; additional regulatory requirements resulting from our continued growth; management's estimates and projections of interest rates and interest rate policy; the execution of our business plan; and other factors affecting the financial services industry generally or the banking industry in particular. Any forward-looking statement made by us in this presentation is based only on information currently available to us and speaks only as of the date on which it is made. We do not intend and disclaim any duty or obligation to update or revise any industry information or forward-looking statements, whether written or oral, that may be made from time to time, set forth in this press release to reflect new information, future events or otherwise. Non-GAAP Financial Measures This presentation contains both financial measures based on GAAP and non-GAAP based financial measures, which are used where management believes them to be helpful in understanding the Company's results of operations or financial position. Where non-GAAP financial measures are used, the comparable GAAP financial measure, as well as the reconciliation to the comparable GAAP financial measure, can be found in the Company's press release as of and for the quarter ended December 31, 2022. These disclosures should not be viewed as a substitute for operating results determined in accordance with GAAP, nor are they necessarily comparable to non-GAAP performance measures that may be presented by other companies. WA Western Alliance Bancorporation® 2#3Western Alliance Bancorporation Overview The Bank for All Seasons A national banking platform of specialized financial services paired with attractive regional markets provides complementary, diversified revenue streams and high operating leverage to produce industry-leading financial results Summary NYSE Headquarters WAL Phoenix, AZ IPO Market Cap¹ 2005 $8.2bn Offices 56 Serving a wide range of commercial and consumer related clients nationwide, from corporate and small business to public and non-profit borrowers Diversified business model provides flexibility and responsiveness to changing winds and market conditions to provide long-term superior risk- adjusted returns BANK DIRECTOR S&P GLOBAL MI FORBES One of Forbes' "America's Best Banks" Year After Year AMERICAN BANKER #1 Bank Above $50B, #1 Best Emerging 2022 Regional Bank & Top 10 U.S. Banks for Growth Strategy #2 Best-Performing of the 50 Largest Public U.S. Banks, 2021 INSTITUTIONAL INVESTOR MAG 2022 All-America Executive Team Best CEO & Best CFO Total Assets $67.7bn NPAs/Assets³ 0.14% LTM NCOs/ Avg. Loans 0.00% Employees 3,300+ LTM PPNR Growth 25.7% LTM ROTCE² 25.4% TBV per Share 5-Year CAGR 16.2% WA Western Alliance Bancorporation® Note: Financial data as of December 31, 2022; 1) Market data as of February 10, 2023; 2) Refer to slide 2 for further discussion of Non-GAAP financial measures. 3) Nonperforming assets includes nonaccrual loans and repossessed assets || 3#44th Quarter 2022 | Financial Highlights Highlights Earnings & Profitability Q4-22 Q3-22 Q4-21 Earnings per Share $2.67 $2.42 $2.32 Net Income EPS Net Income $293.0 $264.0 $246.0 Net Revenue $701.2 $663.9 $561.0 $293.0 million $2.67 Pre Provision Net Revenue¹ $367.8 $358.1 $323.2 Net Interest Margin 3.98% 3.78% 3.33% Efficiency Ratio¹ 46.9% 45.5% 41.8% PPNR1 ROAA 1.67% 1.53% 1.69% ROTCE¹ 27.0% 24.9% 25.8% Balance Sheet & Capital Total Loans $51,862 $52,201 $39,075 Total Deposits $53,644 $55,589 $47,612 CET1 Ratio 9.3% 8.7% 9.1% TCE Ratio¹ 6.5% 5.9% 7.3% Tangible Book Value per Share¹ $40.25 $37.16 $37.84 Asset Quality Provision for Credit losses $3.1 $28.5 $13.2 Net Charge-Offs (Recoveries) $1.8 $(1.9) $1.4 Net Charge-Offs (Recoveries) /Avg. Loans 0.01% (0.02)% 0.02% Q4: $367.8 million 14% YoY Loan Growth Q4: $(0.3) billion 28% YoY4 Tangible Book Value PER SHARE¹ $40.25 ROTCE/ (ex. AOCI)1 27.0% / 23.1% Deposit Growth Q4: $(1.9) billion 13% YoY NPAs²/ Total Assets Total Loan ACL/Funded HFI Loans³ NPAs2/Total Assets 0.69% 0.14% 0.68% 0.74% 0.14% 0.15% 0.15% 6% YoY Dollars in millions, except EPS 1) Refer to slide 2 for further discussion of Non-GAAP financial measures. WA Western Alliance 2) Nonperforming assets includes nonaccrual loans and repossessed assets. Bancorporation® 3) Ratio includes an allowance for credit losses of $21.9 million as of December 31, 2022 related to a $12.0 billion pool of loans covered under 5 separate credit linked notes. YoY loan growth excludes Early Buyout loans that were transferred from HFS to HFI during 2022, with a balance of $1.9 billion at December 31, 2022. 4#5WAL's Value Proposition 1 Leading national commercial bank with unique combination of sustained high-quality growth, leading profitability, and dependable earnings WA Flexible business model - sustainable growth across market cycles. Specialized, high quality loan portfolio - deep client segment expertise and underwriting acumen 2 3 Demonstrated conservative credit culture - superior through-cycle asset quality 4 Differentiated deposit franchise - specialized, national channels serving secularly strong industries LO 5 Leading efficiency produces strong operating leverage 6 Οι 7 Industry-leading profitability - sustained PPNR growth Shareholder-focused capital management - robust TBV per share accumulation 8 Consistent, superior earnings performance Western Alliance Bancorporation® LO 5#6WAL's Thoughtful Evolution Deliberate evolution from a Nevada-focused community bank to a national commercial bank New Business Lines Key Corporate Events Total Assets ($Bn) 4Q'02 $0.9 2Q'05 $2.6 4Q'09 $5.8 1994 Founded as Bank West of Nevada Dec-2002 WAL investors acquire to expand regionally BANK OF 2005 IPO NEVADA FIRST INDEPENDENT BANK 2015 Acquisition of Bridge Bank Nevada Community Bank (1994 - 2002) Nascent Regional Bank (2003 - 2009) Alliance Bank OF ARIZONA Alliance Association BankⓇ TORREY PINES BANK WA Western Alliance BancorporationⓇ 2003 Opened de novo Alliance Bank of AZ 2003 Opened de novo Torrey Pines Bank in SoCal HOA Services ('08) 2Q'14 $10.0 4Q'17 2Q'19 3Q'21 4Q'22 $20.3 $25.3 $52.8 $67.7 2016 2021 Acquisition Crossed of GE Hotel Finance Portfolio $50B in assets 2021 Acquisition of AmeriHome Mortgage BridgeBank Regional Bank with a National Reach (2010 - 2017) National Business Lines Specialized Mortgage Services ('10) Municipal / Public Finance ('11) Resort Finance ('12) Technology & Innovation ('15) Hotel Franchise Finance ('16) National Commercial Bank (2018 - Present) Gaming ('19) Settlement Services ('19) Business Escrow Services ('20) Digital Asset Banking ('21) Entertainment & Media ('21) Restaurant Franchise Finance ('21) 2021 Partnership with TassatPay to offer blockchain payments 6#7Branch-Lite, National Commercial Bank A national banking platform of specialized financial services, paired with attractive regional markets, provides complementary, diversified revenue streams and high operating leverage to produce superior financial returns WAL's branch network represented by major MSAs Physical office location of business development employees Remote locations of business development employees WA Western Alliance Bancorporation® National Business Line Growth Business development offices primarily driven by loan and deposit initiatives for: - - Bridge Bank / Tech & Innovation Warehouse Lending National CRE Settlement Services - Business Escrow Services - HOA Services 7#8Diversified Business Model Allows Flexibility to Sustain Growth WAL actively adapts business and capital allocation in response to changing external environment Growth trajectory maintained with prudent credit risk management Regional Banking Divisions CRE Technology & Innovation National Business Lines Organic Growth Geographic Growth Diversification Trajectory Residential Mortgages Ample growth potential Superior total Dividends shareholder Capital returns WA Western Alliance Bancorporation® Share Repurchases Lot Banking Risk- Allocation Adjusted Yields Hotel Franchise Finance Deep segment & product expertise supports cyclical business lines Pristine asset quality M&A Risk Management Operating Leverage Municipal & Nonprofit HOA Warehouse Mortgage Banking Lending Capital Corporate Call Lines Finance Highly efficient lending & deposit platforms Note: Illustrative as business objectives are not mutually exclusive and image does not represent full suite of WAL divisions, products and services. 8#9Geography Composition Characteristics Highlights Business Transformation Deliberate business transformation emphasizes underwriting specialization and diversification strategy, which sustains superior asset quality Loan Portfolio: 2010 Community banking focused Nevada concentrated Local business C&I and HNW developers Lending Other 4% C&D Other C&I 10% 20% Residential Warehouse 11% $4.2 Bn CRE, 1% Hotel 2% Owner CRE, Non-Owner Occupied 24% Occupied 28% NV 40.4% CA 21.9% AZ 17.0% Other 20.7% • Loan Portfolio: Q4 2022 National, specialized commercial bank Regional footprint Specialized C&I and institutional sponsor-backed developers 27% of Loans Credit Protected C&D 8% Equity Fund Resources 7% Municipal & Nonprofit Tech & 3% Innovation 4% Other C&I 14% $51.9 Bn Residential 31% Warehouse Lending 11% Hotel Franchise Finance 8% 37.0% CRE, Owner Occupied 3% CRE, Non- Owner Occupied 11% • CA AZ 8.2% NV 5.4% . Other 49.4% Deliberate, decade-long business transformation strategy . Nearly 70% of GFC losses from Q4-09 to Q4-12 came from categories comprising 44% of portfolio at Q4-09, which today makes up <6% of loans . Losses concentrated in Nevada and consumer lending during GFC Since year-end 2013, cumulative NCOs of $29mm vs total ACL of $357mm today No quarterly NCO >$8.2mm (13bps) Diverse mix of regionally-focused commercial banking divisions and nationally-oriented, specialized businesses • • • National reach and deep segment expertise enables selective relationships with strong counterparties, leading profitability and superior company risk management Nevada loan concentration reduction: 40% to 5% National lending diversification: 21% to 49% CRE loan concentration reduction: 54% to 21% 53% of loans in low-to-no-loss categories today WA Western Alliance Bancorporation® 9#10Specialized, High Quality Loan Portfolio Diversified by product, client-type and geography emphasizing underwriting discipline Loans by Product Type Loans by Borrower Type Municipal & Nonprofit 3% Tech & Innovation 4% Equity Fund Resources C&D 8% Warehouse Lending 11% ■Resi. & Consumer 7% 31% ■Const. & Land 40% ■CRE, NOO ■CRE, OO 8% ■C&I Residential 31% 3% 18% • Other C&I 14% CRE, 00 3% Hotel Franchise Finance 8% CRE, NOO 11% Highlights • • Diverse mix of regionally-focused commercial banking divisions & nationally-oriented specialized businesses Leverages deep segment expertise to provide specialized banking services to niche markets across the country Segment-focused model supports superior client value and company risk management National reach enables selective relationships with highest asset quality and profitability Sources of Loan Growth (1Q20 - 4Q22) Loans and Loan Yields Loan CAGR 5.43% 5.23% 5.18% 5.40% 5.62% 5.82% 5.83% 4.79% 4.74% WAL 25.3% $6.8 $27.1 4.32% $39.1 $51.9 $8.4 $11.1 $13.2 $15.1 $17.7 $21.1 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 Peers¹ Median: 13.0% Top Quart.: 14.7% • Dollars in billions WA Western Alliance Bancorporation® 16% Regional Banking 16% Other NBLS 12% Warehouse 11% Lending EFR 45% Residential Accelerated growth in NBLs and Residential has contributed to loan diversification and evolution of strategy into low-to- no-loss loan categories ~68% of 3-year growth in low-to-no-loss categories 1) Peers consist of 33 publicly traded banks headquartered in the US with total assets between $25B and $150B, excluding target banks of pending acquisitions, as of December 31, 2022; Source: S&P Global Market Intelligence. | 10#11Demonstrated Conservative Credit Culture Classified Loans / Loans · Non-Accrual Loans / Loans 2.99% 2.18% 2.09% 2.07% 2.40% 1.80% 1.63% 1.41% 1.39% 1.44% 1.31% 1.87% 1.50% 1.14% 1.14% 1.18% 0.82% 0.70% 0.74% 0.71% 2013 2014 2015 2016 2017 2018 2019 2020 2021 MRQ² 0.24% 1.11% 0.77% 0.81% • 0.73% 0.70% 0.55% 0.55% 0.44% 0.40% 0.56% 0.33% • 0.27% 0.44% 0.43% 0.31% 0.29% 0.27% 0.16% 0.19% 0.16% 2013 2014 2015 2016 2017 2018 2019 2020 2021 MRQ² Net Charge-Offs / Average Loans 0.14% 0.21% 0.17% 0.18% 0.16% 0.15% 0.11% 0.11% 00 0.06% 0.07% 0.02% 0.06% 0.06% 0.01% 0.02% 0.02% 0.01% WA Western Alliance Bancorporation® -0.06% -0.07% 2013 2014 2015 2016 2017 2018 2019 2020 2021 MRQ² WAL Peers --Top Quartile • Highlights A decade of business transformation has resulted in consistent relative outperformance in asset quality and credit metrics Asset quality remained strong during height of the pandemic Improvement / stabilization in non- accruals reflects timely identification and resolution of problem loans before realizing losses Credit mitigation expertise is critical with a weaker macro backdrop • 27% of loan portfolio is now credit protected, consisting of government guaranteed, Credit Linked Notes-protected, and cash secured assets¹ Note: Peers consist of 33 publicly traded banks headquartered in the US with total assets between $25B and $150B, excluding target banks of pending acquisitions, as of December 31, 2022; Source: S&P Global Market Intelligence. 1) As of December 31, 2022, CLNs cover a substantial portion of Equity Fund Resources ($1.6 billion), Residential ($9.7 billion) and Warehouse Lending ($689 million) loans | 11 outstanding. 2) MRQ is Q4-22 for WAL and most peers and Q3-22 for the remainder.#12Demonstrated Conservative Credit Culture Deliberate business transformation, emphasizing underwriting specialization and diversification strategy, has produced sustained superior asset quality with reduced dispersion in realized credit losses 5.25% Annualized Net Charge-Offs (1014 - 4Q22) 3.00% Peer Group 1.20% Maximum of Peers Avg of Peers Minimum of Peers Amount Bank Amount Amount Bank 0.90% Average 38 bps HWC 15 bps < 1 bp WAL Maximum 525 bps HWC 78 bps 13 bps WAL 0.60% 0.30% 0.00% WAL SSB ONB GBCI FCNC.A WTFC EWBC CADE UMPQ FNB VLY WBS PNFP WA Western Alliance Bancorporation® CBSH NYCB NOIZ UBSI FIBK ASB ▲ Max Average • PB BOKF ABCB CMA SNV BKU PACW FULT CFR SFNC TCBI OZK UMBF SBNY HWC Note: Peers consist of 33 publicly traded banks headquartered in the US with total assets between $25B and $150B, excluding target banks of pending acquisitions, as of December 31, 2022; Source: S&P Global Market Intelligence. | 12#13Conservative, Economically Resilient Portfolio Positioning Specialized underwriting expertise and conservative sector allocations position portfolio to withstand economic uncertainty Insured (27%) Resistant (27%) Historically low-to-no-loss loan categories Credit protected, government guaranteed and cash-secured 19% Residential 9% Warehouse Lending Includes Core WH Lending, Note Financing, MSR financing 3% Equity Fund Resources 8% 1% Warehouse Lending Residential • Low LTVs; DQs significantly below national percentages • Equity Fund Resources Capital Call & Subscription LOCs Underwrite LPs behind private funds 4% 4% Early Buyout ("EBO") Resi. & Other Government-Guaranteed or Cash-Secured Assets 3% 2% CRE Industrial & Medical 1% Avg Loss Rate: 0.00% Max Loss Rate: 0.00% WA Western Alliance Bancorporation® Municipal/Public Finance HOA - • Extremely low LTVs; lien in front of homeowner's first mortgage Avg Loss Rate: 0.00% Max Loss Rate: 0.10% Resilient (33%) Limited uncovered collateral risk, underwriting expertise, and strong counterparties 7% Regional CRE - Investor 6% Regional C&I 6% Hotel Franchise Finance (ex-Central Business District) 3% Regional CRE - Owner Occupied 2% Corporate Finance 2% Lot Banking 7% Specialized NBLs • - Gaming Off-strip, middle market gaming companies and tribal gaming enterprises - Resort Timeshare resort developers; hypothecation of consumer receivables Other NBLS Avg Loss Rate: 0.02% Max Loss Rate: 0.16% Note: Average and maximum loss rates are quarterly annualized and from the period of Q1 2014 - Q4 2022. More Sensitive (13%) Categories more directly correlated to economic growth 6% Construction (ex-Lot Banking) Focused on note-on-note financing and Built-to-Rent developments • 4% Tech & Innovation • Established tech firms with operating and financial flexibility, validated product, path to profitability 2% Hotel Franchise Finance (CBD • • only) Large, sophisticated hotel sponsors who operate >25 hotels 90% operate >10 properties with top franchisor flags 1% Small Business, CRA-Related, and Consumer Avg Loss Rate: 0.05% Max Loss Rate: 0.71% | 13#14Highlights Substantial Reserve Levels Reserve levels enhanced by credit protection and low loss loan categories Adjusted Total Loan ACL / Funded Loans: 4Q22 1.34% 1.13% 0.21% 0.06% EBOS³ 0.89% 0.94% 0.05% 0.13% Resi 0.20% 0.69% WAL remains appropriately reserved, especially when considering credit protection from Credit Linked Notes (CLNs) and historically low loss loan categories Total Loan ACL / Funded Loans increased to 0.69% in Q4 as a result of heightened economic uncertainty • Total Loan ACL / Funded Loans less loans covered by CLNs is 0.89% Total Loan ACL / Funded Loans less loans covered by CLNs and select no-to- low-loss loan categories (EFR, Residential, and Mortgage Warehouse) is 1.34% . > 7.5x historical maximum annual loss rate4 Reserves are a multiple of average losses times portfolio duration Estimated weighted average duration of the loan portfolio is < 4 years Total Loan ACL / Funded Loans 1,2 - Loans Covered by CLNs - EFR Loans Residential Loans - Mortgage Warehouse Loans • 1 2 3 4 5 Adj. total ACL covers > 25x of historical average annual loss rate4x duration WA Western Alliance Bancorporation® 1) Total Loan ACL includes allowance for unfunded commitments. 2) Ratio includes an allowance for credit losses of $21.9 million as of December 31, 2022 related to a $12.0 billion pool of loans covered under 5 separate credit linked notes. 3) Early Buyout Loans are government guaranteed. 4) Historical weighted average loss rates from the period of Q1 2014 - Q4 2022, per slide 13. 14#15Highlights Scalable, Differentiated Deposit Franchise Diversified funding channels provide secular growth trends and reflect long- term relationships Deposit Base 18% 9% 36% ■Nonint. Bearing DDA ■MMDA & Savings Deposit Composition ■Regions % 12% 37% Interest Bearing DDA CDs ■Mtg WH 6% Tech & Innov. ■ НОА 12% ~40% of NIB DDAS are ECR-related Sttlmt Svcs Bus. Escrow Svcs 14% Other 16% Deposits, Borrowings, and Cost of Funds 39% 0.86% 0.80% 0.64% 0.39% 0.36% 0.30% 0.31% 0.37% 0.34% 0.25% $7.2 $2.4 $19.7 $1.0 $21.3 $0.4 $0.8 $0.9 $13.4 $0.5 $0.5 $0.4 $0.4 $8.5 $22 $23 $4.1 $5.6 $7.4 $7.5 $33.9 $26.3 $5.6 $6.6 $7.9 $8.9 $9.5 $11.7 $14.3 $18.5 27.6% CAGR 22.1% CAGR 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 Dollars in billions Interest Bearing Deposits Non-Interest Bearing Deposits Total Borrowings Cost of Funds • • • $53.6Bn in total deposits, typically tied to lending relationships • WAL benefits from holding customer's primary relationship Scalable national funding channels, such as HOA, Settlement Services, Business Escrow Services, and Tech & Innovation Core deposits fund balance sheet growth • Deposits comprise 88% of total funding 97% Loan-to-Deposit ratio 37% of total deposits are noninterest- bearing ~40% of which are Earnings Credit Rate-related • Earnings Credit Rate-related deposit balances of $12.9 billion ~62% associated with non-interest bearing accounts WA Western Alliance Bancorporation® Note: Borrowings include customer repurchase agreements; Cost of Funds defined as total expense paid on interest bearing liabilities divided by the sum of average interest- bearing liabilities and average non-interest bearing demand deposits. 15#16Highlights Leading Efficiency Produces Strong Operating Leverage Track record of simultaneously driving industry-leading growth and efficiency Efficiency Ratio 63.0% 62.7% Breakdown of Non-Interest Expenses Salaries & Employee Benefits Other Operating Expenses 60.3% 59.9% 58.8% 56.2% 55.6% 56.5% 57.2% Deposit Costs 53.2% 53.3% $333.4 53.2% 47.8% 47.0% 44.9% 45.0% $305.8 47.6% 43.3% 42.6% 46.9% 41.4% 42.9% $82.2 44.7% 38.8% 42.2% 41.0% 40.7% 42.0% 41.1% 37.9% $237.8 $9.1 $248.6 $9.3 $268.9 $18.1 $56.2 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 $139.0 $136.5 $125.7 $120.6 $138.3 WAL - WAL Adjusted Peers . • • Continued focus on expense management, while investing in growth initiatives and scalable infrastructure to become a leading nationwide banking platform Efficiency ratio¹ increased 200 bps to 44.9% compared to 2021 . Increased 140 bps to 46.9% in Q4 from Q3 Deposit costs increased $26.0 million in Q4 from the prior quarter, primarily related to higher earnings credit rates Efficiency ratio¹ adjusted to reclassify deposit costs as interest expense was 41.1%, compared to 42.0% in 2021 • 40.0% in Q4, compared to 40.5% in Q3 Dollars in millions $125.5 $108.1 $101.0 $111.8 $113.1 Q4-21 Q1-22 Q2-22 Q3-22 Q4-22 WA Western Alliance Bancorporation® Note: Efficiency ratio for WAL and Peers as calculated and reported by S&P Global Market Intelligence. Peers consist of 33 publicly traded banks headquartered in the US with total assets between $25B and $150B, excluding target banks of pending acquisitions, as of December 31, 2022; Source: S&P Global Market Intelligence. 1) Refer to slide 2 for further discussion of Non-GAAP financial measures. | 16#17Industry-Leading Profitability ROAA Pre-Provision Net Revenue ($MM) WAL Peers 2.05% 2.00% 1.83% 1.72% 1.50% 1.56% 1.61% 1.61% 1.62% 1.35% 1.27% 1.21% 1.19% 1.10% 0.93% 0.99% 0.96% 0.96% 0.97% 0.90% 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022¹ CAGR: 27% $624 $533 $469 $369 $262 $159 $202 $746 $1,384 $1,102 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 ROATCE Net Interest Income WAL Peers 4.39% 4.42% 4.51% 4.58% 4.65% 4.68% 4.52% 3.97% 26.2% 25.4% $2,216 3.67% 3.41% 20.6% 18.3% 18.5% 17.8% 17.7% 18.3% 19.6% 17.7% 16.2% 15.1% 15.0% 14.6% 11.9% 11.7% 11.2% 11.6% 11.5% 11.2% $1,549 $1,167 $1,040 $916 $785 $657 $493 $333 $385 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022¹ 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 WA Western Alliance Bancorporation® NII -NIM Highlights • • • Outstanding performance compared to peers with ROAA and ROATCE among highest in industry Net Interest Income continues to rise through strong earning asset growth Net Interest Income increased $668 million, or 43.1%, from 2021 due to strong loan growth and the rising rate environment NIM increased 26 bps, driven by higher yields on interest earning assets PPNR increased $283 million, or 25.7%, from 2021 Note: Peers consist of 33 publicly traded banks headquartered in the US with total assets between $25B and $150B, excluding target banks of pending acquisitions, as of December 31, 2022; Source: S&P Global Market Intelligence. 1) FY2022 for WAL and most peers and Q3-22 four quarter average for the remainder. 17#18Net Interest Drivers Total Investments and Yield Spot Rate 4.56% Spot Rate Loans and HFI Yield 6.26% 4.45% 5.70% 3.66% 4.84% 2.77% 2.94% 2.51% 4.03% 4.19% 3.98% • $8.8 $2.2 $8.3 $8.6 $8.8 $2.8 $1.2 $7.5 $5.6 $4.8 $51.9 $52.2 $48.6 $39.1 $41.1 Q4-21 Q1-22 Q2-22 Q3-22 Q4-22 Total Investments Q4-21 Q1-22 Loans Q2-22 Q3-22 Loans, HFS Q4-22 Interest Bearing Deposits and Cost Spot Rate 2.21% Spot Rate Deposits, Borrowings & Cost of Liability Funding 1.88% 1.57% 1.97% 0.88% 1.03% 0.37% 0.25% 0.27% 0.38% 0.20% 0.21% $1.7 $6.1 $7.2 $7.2 $2.4 $33.9 $23.5 $23.7 $24.9 $19.7 $21.3 $30.0 $30.7 $28.6 $26.3 $33.9 $26.3 $28.6 $30.0 $30.7 Q4-21 Q1-22 Q2-22 Q3-22 Q4-22 Q4-21 Interest Bearing Deposits Dollars in billions, unless otherwise indicated WA Western Alliance Bancorporation® Q1-22 Q2-22 Q3-22 Q4-22 Interest Bearing Deposits Non-Interest Bearing Deposits ■Total Borrowings Highlights • Loan yields increased 86 bps in Q4 due to a higher rate environment Yield on Loans Held for Sale of 5.63% increased from 4.87% in Q3 Investment yields increased 79 bps in Q4, primarily related to floating-rate securities • Cost of interest-bearing deposits increased 94 bps, and total cost of funds increased 69 bps in Q4 to 1.57% due to higher costs on deposits and borrowings | 18#19Net Interest Income Sensitivity WA Static Balance Sheet ■Growth Balance Sheet 1 Static Balance Sheet ■Growth Balance Sheet1 Highlights NII Sensitivity - Shock Scenario, +100 bps 3.1% 12 months >20% WAL expects a 3.1% increase in NII under a +100 bps rate shock on a static balance sheet 52% of loans (ex-HFS) are contractually variable ($27.1 billion) . 73% of variable rate loans have rate floors Moderate NII sensitivity, driven primarily by balance sheet movement rather than changes in the rate environment NII Sensitivity - Shock Scenario, -100 bps -3.0% 12 months >10% Western Alliance Bancorporation® 1) For illustrative purposes only and not intended as guidance. || 19#20Shareholder-Focused Capital Management WAL consistently generates more capital than needed to support organic growth Robust Capital Levels 11.4% 11.5% 11.3% 11.5... 11.5% 11.1% 11.1% 10.9% 11.1... 10.5% 9.7% 10.0% 10.4% 0.6% 9.3% 10.7% 9.9% 8.8% 9.6% 10.2% 10.3% 9.1% 9.3% 8.6% 9.4% 8.6% 8.1% - 8.6% 9.1% 7.9% 8.8% 9.0% 8.3% 8.5% 8.1% 7.4% 7.3% 6.5% 2013 2014 2015 2016 2017 CET1 Peer CET11 2018 TCE/TA 2019 2020 2021 MRQ¹ Peer TCE/TA¹ Long Term Growth in TBV per Share WAL WAL with Dividends Added Back 461% 411% Peer Avg Peer Avg with Dividends Added Back Total Shareholder Return Highlights Common Equity Tier 1 . CET1 remains healthy at 9.3% 7.1% Tangible Common Equity / Tangible Assets² • TCE / TA decreased 80 bps from 2021 to 6.5%, primarily due to strong asset growth and AOCI loss impact TBV Growth and Total Shareholder Return • • 19.9% TBVPS CAGR since year end 2013 TBVPS has increased more than 4x that of peers Strong returns bolster capital appreciation above peers • • WAL produces ~45 bps of CET1 per quarter on a static balance sheet WAL produced 60 bps of CET1 during Q4-22 through strategic capital management levers WAL Peer Top | Quartile Peer Median 1 Year -23% -1% -7% 130% 3 Year 40% 41% 26% 5 Year 38% 31% 17% 10-Year 516% 206% 129% 99% 2013 2014 2015 2016 2017 2018 2019 2020 2021 MRQ¹ WA Western Alliance Bancorporation® Note: Peers consist of 33 publicly traded banks headquartered in the US with total assets between $25B and $150B, excluding target banks of pending acquisitions, as of December 31, 2022. TSR through February 10, 2023. Source: S&P Global Market Intelligence. MRQ is Q4-22 for WAL and most peers and Q3-22 for the remainder. Refer to slide 2 for further discussion of Non-GAAP financial measures. | 20#21Consistently Strong Earnings Trajectory WAL's excess, risk-adjusted earnings growth normalized for historical volatility Relative Rankings Highest Avg. EPS Lowest 135 4 85 A Consistency B Valuation B/A Combined Avg. Std "EPS Bank WAL - Risk-Free Rate Dev. Sharpe" 2023 P/E Rank 3 11 = 1.31 7.3 1 FCNC.A 9 6 = 0.96 8.3 2 SBNY 8 8 = 0.93 8.6 ABCB 2 EWBC 12 PNFP 6 ASB 24 WTFC 14 GBCI 21 HWC 16 ZION 4 OZK 11 UMBF CADE CFR PB FULT CMA SFNC CBSH SSB TCBI WBS PACW SNV BKU UBSI 29 UMPQ FIBK 28 2122277351222022 18 22215422267527523 = 0.80 9.4 9 = 0.76 8.4 = 0.71 10.7 = 0.70 9.1 6 = 0.58 8.7 7 = 0.57 17.7 20 = 0.54 8.6 11 29 = 0.52 8.1 9 = 0.50 8.0 10 18 0.49 10.8 14 0.45 9.3 13 0.44 12.3 17 1437 = 0.38 12.7 23 = 0.38 9.0 15 = 0.37 7.6 12 = 0.36 11.0 19 0.35 16.4 28 33 0.35 9.7 16 34 0.31 16.5 30 26 0.28 7.9 18 19 28 0.26 8.2 21 30 = 0.26 8.2 22 32 = 0.25 9.7 25 12 = 0.24 14.1 32 10 = 0.21 7.8 24 20 = 0.20 10.5 31 VLY 30 16 = 0.20 8.7 27 ONB 27 21 0.19 8.2 26 FNB 26 24 0.18 8.8 29 BOKF 33 19 = 0.18 NYCB 34 3 = 0.07 10.9 8.5 33 34 Highlights Profitability Leadership Maintained Through Business Diversification WAL's risk-adjusted net income growth has significantly outperformed peers since 2013 • Strong earnings growth has been accompanied by lower-than-peer earnings volatility • . WAL is No. 3 in excess earnings growth and No. 11 in low volatility • WAL is No. 1 in the two metrics combined, with the strongest consistency of earnings Closest competitors scored 0.93-0.96 with peer median > 3.5x below WAL Bank WAL Top-5-Peer Median Top Third-Peer Median Top Two-Thirds - Peer Median 10-Year Excess Risk-Adj. EPS Growth 1.31 0.80 0.70 0.49 Peer Median 0.37 WAL is No. 1 on valuation (P/E multiple to earnings growth) WA Western Alliance Bancorporation® Note: Peers consist of 33 publicly traded banks headquartered in the US with total assets between $25B and $150B, excluding target banks of pending acquisitions, as of December 31, 2022. YTD results annualized for full year comparisons with consensus EPS projections. Risk-free rate is the average daily 10-year Treasury rate. P/E multiples as of February 10, 2023. Source: S&P Global Market Intelligence. | 21#22WA Western Alliance Bancorporation® Appendix#23Unique Mortgage Banking Platform That Enhances Growth, Returns and Diversification 1 HFS Loans Deploy excess liquidity into HFS loans as a higher yielding, equally liquid alternative to cash 2 Custodial Deposits Enhance Earning Asset Mix Augments stable funding Access to $3.5 billion of core deposits Correspondent Servicing/ Lending (GOS) MSR Sales Maximize Client Relationships Adjust "Win Rate" AmeriHome Stability Levers Consumer Direct (Refi. Recapture) Enhance Deposit Franchise New Products Jumbo & Non-QM Early Buy Outs (EBOs) 4 Direct Mortgage Offering • Explore new customer acquisition strategies beyond WAL synergies HOA leads - Lot banking WAL client referrals WA Western Alliance Bancorporation® Optimize Mortgage Warehouse Franchise 3 Warehouse Lending Launch AMH referral process with WAL warehouse lending team • Cross-sell warehouse lending loans into AMH's clients | 23#24Credit-Linked Note (CLN) Trade Dynamics Issuing CLNs enables WAL to optimize the amount of capital held against loans in the reference portfolio and reduces credit tail risk Capital Savings Pre-Trade Post-Trade Risk-Weighted Asset Relief CLN/ Credit Protection A $228MM @ 5.52% 0% RW A $228MM x 50% = $114MM $1.4Bn x 10%²= $140MM Residential Loan B ($4.6Bn-$228MM) x (50%-20%) = $1.3Bn Prevented issuance of ~1.3MM common shares³ B Portfolio $4.8B 50% RW Reference Portfolio / Total RWA Relief: Retained Senior Risk $4.6B 20%¹ RW $114MM +$1.3Bn = $1.4Bn Agency Jumbo QM Non- QM WA Western Alliance Bancorporation® · Note: Representation of WAL's 4Q21 CLN transaction Minimum risk weighting required to be applied to the exposure 10% CET1 floor assumption Assumes share price as of close date of CLN trade, 12/29/21 CLN Benefits Supports incremental loan growth and earnings • Provides first loss credit protection Serves as additional alternative to selling shares of common equity • Contributes to stability of CET1 ratio | 24#25WA Western Alliance Bancorporation®