EAST WEST BANCORP INC

The Company maintains a portfolio of high quality and liquid debt securities with a moderate duration profile. It closely manages the overall portfolio credit, interest rate and liquidity risks. The Company’s debt securities provide:

•interest income for earnings and yield enhancement;

•funding availability for needs arising during the normal course of business;

•the ability to execute interest rate risk management strategies in response to changes in economic or market conditions; and

•collateral to support pledging agreements as required and/or to enhance the Company’s borrowing capacity.

While the Company does not intend to sell or trade its debt securities, it may sell AFS debt securities in response to changes in the balance sheet and related interest rate risk to meet liquidity, regulatory and strategic requirements.

The following table presents the distribution of the Company’s AFS and HTM debt securities portfolio by amortized cost and fair value as of March 31, 2026 and December 31, 2025, and by credit ratings as of March 31, 2026:

(1)Credit ratings represent independent assessments of the credit quality of debt securities. The Company determines the credit rating of a debt security based on the lowest rating assigned by any of the nationally recognized statistical rating organizations (“NRSROs”) that have rated the security. Investment grade debt securities are those with ratings similar to BBB- or above (as defined by NRSROs), and are generally considered by the rating agencies and market participants to be low credit risk. Ratings percentages are allocated based on fair value.

(2)Includes Government National Mortgage Association (“GNMA”) AFS debt securities with amortized cost and fair value both totaling $10.3 billion and $9.6 billion as of March 31, 2026 and December 31, 2025, respectively.

(3)Includes GNMA HTM debt securities totaling $77 million of amortized cost and $63 million of fair value as of March 31, 2026, and $79 million of amortized cost and $65 million of fair value as of December 31, 2025.

The Company’s AFS and HTM debt securities portfolios had an effective duration (defined as the sensitivity of the value of the portfolio to interest rate changes) of 3.5 and 5.7, respectively, as of March 31, 2026, compared with 3.0 and 5.9, respectively, as of December 31, 2025. The AFS debt securities’ effective duration increased primarily due to the purchase of new fixed‑rate AFS securities, coupled with the sale of floating‑rate AFS securities, while the decline in the HTM debt securities’ effective duration is mainly due to the portfolio run-off.

Available-for-Sale Debt Securities

AFS debt securities increased $881 million or 7% from December 31, 2025 to $14.1 billion as of March 31, 2026, primarily due to the purchases of GNMA securities. The Company’s AFS debt securities are carried at fair value with non-credit related unrealized gains and losses, net of tax, reported in Other comprehensive income (loss)on the Consolidated Statement of Comprehensive Income. Pre-tax net unrealized losses on AFS debt securities were $453 million as of March 31, 2026, compared with $406 million as of December 31, 2025.

Of the AFS debt securities with gross unrealized losses, substantially all were rated investment grade as of both March 31, 2026 and December 31, 2025. For additional information on the policies, methodologies and judgments used to determine the allowance for credit losses on AFS debt securities, see Item 8. Financial Statements — Note 1 — Summary of Significant Accounting Policiesto the Consolidated Financial Statements in the Company’s 2025 Form 10-K and Note 4 — Securities to the Consolidated Financial Statements in this Form 10-Q.

Held-to-Maturity Debt Securities

All HTM debt securities were issued, guaranteed, or supported by the U.S. government or government-sponsored enterprises. Accordingly, the Company applied a zero credit loss assumption for these securities and no allowance for credit loss was recorded as of both March 31, 2026 and December 31, 2025.

For additional information on AFS and HTM securities, see Note 1 — Summary of Significant Accounting Policiesto the Consolidated Financial Statements in the Company’s 2025 Form 10-K and Note 2 — Fair Value Measurement and Fair Value of Financial Instruments and Note 4 — Securities to the Consolidated Financial Statements in this Form 10-Q.