Onto Innovation Inc. filed a current report on August 10, 2026, disclosing the completed acquisition of a 27% equity stake in Rigaku Holdings Corporation for approximately $720 million.

Key Highlights

  • Transaction closed: The acquisition was completed on August 10, 2026 (Tokyo time), according to the filing.
  • Shares acquired: Onto Innovation purchased 61,123,436 shares of Rigaku Holdings Corporation common stock, representing 27% of issued and outstanding shares.
  • Purchase price: The aggregate purchase price was approximately $720 million.
  • Seller: Shares were purchased from Atom Investment, L.P., described in the filing as an affiliate of The Carlyle Group.
  • Original agreement: The Share Purchase Agreement was dated April 21, 2026, and was previously announced.
  • Exchange and ticker: Onto Innovation common stock is listed on the New York Stock Exchange under the symbol ONTO.

Onto Innovation Acquires 27% of Rigaku Holdings for $720 Million

Onto Innovation Inc. (NYSE: ONTO) disclosed in an 8-K filed August 10, 2026, that it had completed its previously announced purchase of a minority stake in Rigaku Holdings Corporation. According to the filing, the transaction closed on August 10, 2026 (Tokyo time), with the company acquiring 61,123,436 shares of Rigaku common stock, equal to 27% of that company's issued and outstanding shares, for an aggregate purchase price of approximately $720 million.

The filing identifies the seller as Atom Investment, L.P., described as an affiliate of The Carlyle Group. The underlying Share Purchase Agreement was dated April 21, 2026, and a copy was previously filed as Exhibit 2.1 to a current report submitted to the Securities and Exchange Commission on April 20, 2026. The filing notes that the description of the Purchase Agreement "is qualified in its entirety by reference to the full text of the Purchase Agreement."

Under Item 7.01, the company reported that it issued a press release on August 10, 2026, announcing the closing. The filing specifies that the information disclosed under Item 7.01, including the attached press release (Exhibit 99.1), "shall be deemed furnished and not 'filed'" for purposes of Section 18 of the Securities Exchange Act of 1934. The report was signed by Yoon Ah Oh, Senior Vice President, General Counsel and Corporate Secretary. The filing also contains forward-looking statements, which the company cautions "may differ materially from those projected as a result of various factors," and notes these are subject to its cautionary language under the Private Securities Litigation Reform Act of 1995.

What Was Disclosed

Onto Innovation reported the August 10, 2026, closing of its purchase of 61,123,436 shares, or 27%, of Rigaku Holdings Corporation common stock from Atom Investment, L.P. for approximately $720 million, under a Share Purchase Agreement dated April 21, 2026.