NOTE 15. Subsequent Event

On April 20, 2026, the Company entered into a definitive share purchase agreement (“the Transaction”) with Atom Investment, L.P., an affiliate of The Carlyle Group, to acquire 27% of the outstanding common stock of Rigaku Holdings Corporation (“Rigaku”) for approximately $710 million. In connection with the Transaction, Onto Innovation Inc. will receive the right to nominate one director to Rigaku’s board. The Company expects to account for the minority investment under the fair value option method and will not consolidate financial results. The transaction is expected to close in the second half of 2026.

Also on April 20, 2026, the Company entered into a commitment letter with Goldman Sachs Bank USA, which provides for a senior secured 364-day $500 million bridge term loan credit facility. The bridge term loan is intended to be available to the Company to finance, together with other sources of funds, the Transaction and related fees and expenses on or prior to the closing of the Transaction.