ONTO

• The shares were purchased from Atom Investment, L.P., an affiliate of The Carlyle Group, under a Share Purchase Agreement dated April 21, 2026.
• The aggregate purchase price was approximately $720 million (113,078,356,600 yen).
• Onto Innovation will account for the investment under the fair value option method and will not consolidate Rigaku's financial results.
• Onto Innovation will nominate a director to serve on Rigaku's board, deepening the strategic collaboration to advance X-ray-based process control for semiconductor manufacturing.

2.01 Completion of Acquisition or Disposition of Assets · 7.01 Regulation FD Disclosure · 9.01 Financial Statements and Exhibits

• Record quarterly revenue of $343.1 million, up 35.3% year-over-year from $253.6 million in Q2 2025.
• GAAP diluted EPS was $1.21; non-GAAP diluted EPS was $1.93.
• Backlog exceeded $1 billion for the first time in company history.
• Q3 2026 guidance: revenue of $380M-$400M, non-GAAP diluted EPS of $2.18-$2.38.

2.02 Results of Operations and Financial Condition · 9.01 Financial Statements and Exhibits

• The notes mature on June 1, 2031, are senior unsecured obligations, and are convertible at an initial conversion rate of 2.6192 shares per $1,000 principal, equivalent to an initial conversion price of approximately $381.80 per share.
• The company entered into capped call transactions with financial institutions to reduce potential dilution upon conversion, with an initial cap price of $509.06 per share.
• Concurrently, the company used $204,979,372.25 of net proceeds to repurchase 805,325 shares of its common stock at $254.53 per share in privately negotiated transactions.
• The notes were offered and sold in reliance on Section 4(a)(2) of the Securities Act and Rule 144A to qualified institutional buyers.

1.01 Entry into a Material Definitive Agreement · 2.03 Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement · 3.02 Unregistered Sales of Equity Securities · 8.01 Other Events · 9.01 Financial Statements and Exhibits

• Onto Innovation Inc. held its 2026 Annual Meeting on May 20, 2026, in Wilmington, Massachusetts.
• The advisory (non-binding) vote on named executive officer compensation passed with 40,624,022 votes for, 1,196,481 against, and 201,194 abstentions.
• Stockholders ratified Ernst & Young LLP as the independent registered public accounting firm for fiscal year ending December 31, 2026, with 44,378,549 votes for, 178,157 against, and 147,375 abstentions.
• The report was filed under Item 5.07 to disclose the results of these stockholder votes.

5.07 Submission of Matters to a Vote of Security Holders · 9.01 Financial Statements and Exhibits

• The company expects to grant initial purchasers an option to buy up to an additional $165,000,000 of notes.
• Proceeds will fund capped call transactions, up to approximately $300,000,000 for concurrent share repurchases, and general corporate purposes including financing the previously announced acquisition of 27% of Rigaku Holdings Corporation.
• The notes will be senior unsecured obligations maturing on June 1, 2031, unless earlier converted, redeemed, or repurchased.
• The offering is subject to market conditions and other factors; the press release was filed as Exhibit 99.1 to the Form 8-K.

8.01 Other Events · 9.01 Financial Statements and Exhibits

• Revenue for Q1 2026 was $291.9 million, a 9.5% increase from $266.6 million in Q1 2025.
• Non-GAAP net income was $70.8 million, or $1.42 diluted EPS, compared to $74.8 million, or $1.51, in Q1 2025.
• The company announced a strategic collaboration with Rigaku, including a 27% ownership stake for approximately $710 million, expected to close in H2 2026.
• Q2 2026 guidance: revenue of $320-$330 million, non-GAAP diluted EPS of $1.65-$1.73.

2.02 Results of Operations and Financial Condition · 9.01 Financial Statements and Exhibits

• The transaction is expected to close in the second half of 2026, subject to regulatory approvals and other customary closing conditions.
• Onto Innovation will receive the right to nominate one director to Rigaku's board and will account for the investment under the fair value option method without consolidating Rigaku's results.
• The companies are collaborating on X-ray metrology solutions, integrating Onto's Ai Diffract software with Rigaku's CD-SAXS platforms, with two key customers already selected.
• Onto Innovation secured a $500 million bridge loan commitment from Goldman Sachs Bank USA to help finance the transaction.

1.01 Entry into a Material Definitive Agreement · 7.01 Regulation FD Disclosure · 8.01 Other Events · 9.01 Financial Statements and Exhibits

• Q2 2026 revenue guidance is set at $320–330 million, an 8% increase over the previously shared outlook.
• The Dragonfly G5 system was qualified for 2.5D AI packaging applications, with initial shipments expected in June.
• Dragonfly platform demand is expected to grow more than 50% in 2026 compared with 2025.
• Full Q1 financial results will be released after market close on May 5, 2026.

2.02 Results of Operations and Financial Condition · 9.01 Financial Statements and Exhibits