Investor Presentaiton

Highlights Demonstrated Conservative Credit Culture Classified Loans / Loans • Non-Accrual Loans / Loans 2.99% 1.11% 0.81% 0.77% 2.56% 2.10%2.10% 2.03% 0.73% 0.74% 1.77% 1.62% 0.55% 0.50% 1.37%1.39% 1.40% 1.87% 1.23%1.23% 0.44% 0.56% °0.40% 1.50% 0.33% 0.34% 0.27% 0.44% 1.14% 1.14%1.18% 0.43% 0.70% 0.82% 0.74% 0.70% 0.93% 0.31% 0.29% 0.27% 0.23% 0.16% 0.19%0.16% 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 MRQ¹ 0.25% 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 MRQ' Net Charge-Offs / Average Loans 0.19% 0.18% 0.16%0 0.15%0.15% 0.14% 0.13% 0.12% . • • 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 A quarter of the loan portfolio is credit protected, consisting of government guaranteed, Credit Linked Notes-protected, and cash secured assets² WA Western Alliance Bancorporation® 0.10% 9.06%0.06% 0.02% 0.06% 0.06% 0.05% 0.01% 0.02% 0.02% 0.00% -0.07% -0.06% 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 MRQ' WAL Peers --Top Quartile Note: Peers consist of 34 publicly traded banks headquartered in the U.S. with total assets between $25B and $150B as of March 31, 2023 Source: S&P Global Market Intelligence 1) MRQ is 1Q23 for WAL and some peers and 4Q22 for the remainder 2) As of March 31, 2023, CLNs cover a substantial portion of Residential ($9.5 billion) loans outstanding | 13

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