Robert T. Ishii
Partner
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Leader of Mergers and Acquisitions Group
Rob's M&A practice focuses on contests for corporate control and other complex strategic transactions, including divestitures and joint ventures.
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Experienced Practitioner
Rob's transactional experience includes recent M&A transactions valued over $100 billion.
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Represents Leading Companies
Rob has represented the likes of Microchip, Lumentum, Pacific Biosciences, Omnivision, Varian, Logitech, Google, and Twitter.
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Other Roles
Rob is involved in the management of the firm and San Francisco office, and has served on the firm's Compensation Committee, Policy Committee, and Nominating Committee.
Robert Ishii is a partner in Wilson Sonsini Goodrich & Rosati's San Francisco office and is the leader of the firm's mergers and acquisitions group. His practice focuses on mergers and acquisitions, contests for corporate control, and other complex strategic transactions, including divestitures, joint ventures, and other transformative transactions.
He has represented public and private companies, private equity funds, and financial advisors in negotiated and hostile transactions in the technology, medical technology, biotechnology, media, telecommunications, and other industries.
Rob is active in the management of the firm and the San Francisco office. He has served on the firm’s Compensation Committee, Policy Committee, and Nominating Committee.
Experience
Robert Ishii is a partner in Wilson Sonsini Goodrich & Rosati's San Francisco office and is the leader of the firm's mergers and acquisitions group. His practice focuses on mergers and acquisitions, contests for corporate control, and other complex strategic transactions, including divestitures, joint ventures, and other transformative transactions.
He has represented public and private companies, private equity funds, and financial advisors in negotiated and hostile transactions in the technology, medical technology, biotechnology, media, telecommunications, and other industries.
Rob is active in the management of the firm and the San Francisco office. He has served on the firm’s Compensation Committee, Policy Committee, and Nominating Committee.
Education
- J.D., University of Chicago Law School
- A.B., Cornell University
Honors
- Named in the 2023-2026 editions of Chambers USA: Leading Lawyers for Business as a top corporate/M&A attorney in San Francisco, Silicon Valley, and Surrounds
- Selected for inclusion in the 2016-2026 editions of Who's Who Legal: M&A (and successor Lexology)
- Recognized as a "Life Science Star" in the finance and transactional section of LMG Life Sciences in 2013-2026
Admissions
- State Bar of California
- State Bar of New York
Credentials
Education
- J.D., University of Chicago Law School
- A.B., Cornell University
Honors
- Named in the 2023-2026 editions of Chambers USA: Leading Lawyers for Business as a top corporate/M&A attorney in San Francisco, Silicon Valley, and Surrounds
- Selected for inclusion in the 2016-2026 editions of Who's Who Legal: M&A (and successor Lexology)
- Recognized as a "Life Science Star" in the finance and transactional section of LMG Life Sciences in 2013-2026
Admissions
- State Bar of California
- State Bar of New York
Select Transactions
- Edgewise in its $2.65 billion sale of Sevasemten to Servier
- Arcellx in its $7.8 billion acquisition by Gilead
- Soleno Therapeutics in its $2.9 billion acquisition by Neurocrine
- Excellergy in its up to $2 billion acquisition by Novartis
- Ventyx in its $1.2 billion acquisition by Lilly
- Evercore as financial advisor in connection with Longboard Pharmaceutical’s $2.6 billion acquisition by Lundbeck
- Recursion Pharmaceuticals in its $688 million merger with Exscientia
- Silk Road Medical in its $1.3 billion acquisition by Boston Scientific
- DTx Pharma in its $1 billion acquisition by Novartis
- Sierra Oncology in its $1.9 billion acquisition by GSK
- Bungie in its $3.6 billion acquisition by Sony Interactive Entertainment
- Pharmacyclics in its $21 billion acquisition by AbbVie
- Stemcentrix' founder and principal stockholder in its $6 billion acquisition by AbbVie
- Seragon Pharmaceuticals in its acquisition by Roche for up to $1.7 billion
- Aragon Pharmaceuticals in its acquisition by Johnson & Johnson for up to $1 billion, and in the related spinoff of Seragon Pharmaceuticals
- Rocket Lab in its $8 billion acquisition of Iridium
- Special Committee of Globalstar in its $11.6 billion acquisition by Amazon
- Marvell Technology
- up to $5.5 billion acquisition of Celestial.ai
- $540 million acquisition of Xconn Technologies
- $2.5 billion sale of Automotive Ethernet business to Infineon
- Lumentum
- $750 million acquisition of Cloud Light Technology
- $920 million acquisition of NeoPhotonics
- $6.9 billion aborted acquisition of Coherent, after public bidding war
- $1.8 billion acquisition of Oclaro
- Microchip in its $10.2 billion acquisition of Microsemi
- DoorDash in its $8 billion acquisition of Wolt Enterprises
- Pismo in its $1 billion acquisition by Visa
- MaxLinear in its aborted $3.8 billion acquisition of Silicon Motion
- Talend in its $2.4 billion acquisition by Thoma Bravo
- Gogoro in its $2.35 billion de-SPAC merger with Poema Global
- Pacific Biosciences in its $1.2 billion acquisition by Illumina (aborted)
- Neotract in its acquisition by Teleflex for up to $1.1 billion
- Microchip in its $3.6 billion acquisition of Atmel, after the termination of its existing transaction with Dialog Semiconductor
- HomeAway in its $3.9 billion acquisition by Expedia
- Microchip Technology in its $840 million acquisition of Micrel
- Integrated Silicon Solution Inc. (ISSI) in its $800 million acquisition by a Chinese investment group led by SummitView Capital, after a public bidding war with Cypress Semiconductor
- Omnivision in its pending $1.9 billion acquisition by an investment group led by Hua Capital
- Technicolor in its $600 million acquisition of Cisco's Connected Device Division
- Microchip Technology in its $940 million acquisition of Standard Microsystems Corp.
- Calistoga Pharmaceuticals in its acquisition by Gilead Sciences for up to $600 million
- Ardian in its acquisition by Medtronic for up to $1.5 billion
- Varian in its $1.5 billion acquisition by Agilent Technologies
- Acclarent in its $785 million acquisition by Ethicon (a Johnson & Johnson company)
- Wind River Systems in its $900 million acquisition by Intel
- CoreValve in its $775 million acquisition by Medtronic
- Francisco Partners in $720 million sale of Metrologic Instruments
- Google in multiple acquisitions
Matters
Select Transactions
- Edgewise in its $2.65 billion sale of Sevasemten to Servier
- Arcellx in its $7.8 billion acquisition by Gilead
- Soleno Therapeutics in its $2.9 billion acquisition by Neurocrine
- Excellergy in its up to $2 billion acquisition by Novartis
- Ventyx in its $1.2 billion acquisition by Lilly
- Evercore as financial advisor in connection with Longboard Pharmaceutical’s $2.6 billion acquisition by Lundbeck
- Recursion Pharmaceuticals in its $688 million merger with Exscientia
- Silk Road Medical in its $1.3 billion acquisition by Boston Scientific
- DTx Pharma in its $1 billion acquisition by Novartis
- Sierra Oncology in its $1.9 billion acquisition by GSK
- Bungie in its $3.6 billion acquisition by Sony Interactive Entertainment
- Pharmacyclics in its $21 billion acquisition by AbbVie
- Stemcentrix' founder and principal stockholder in its $6 billion acquisition by AbbVie
- Seragon Pharmaceuticals in its acquisition by Roche for up to $1.7 billion
- Aragon Pharmaceuticals in its acquisition by Johnson & Johnson for up to $1 billion, and in the related spinoff of Seragon Pharmaceuticals
- Rocket Lab in its $8 billion acquisition of Iridium
- Special Committee of Globalstar in its $11.6 billion acquisition by Amazon
- Marvell Technology
- up to $5.5 billion acquisition of Celestial.ai
- $540 million acquisition of Xconn Technologies
- $2.5 billion sale of Automotive Ethernet business to Infineon
- Lumentum
- $750 million acquisition of Cloud Light Technology
- $920 million acquisition of NeoPhotonics
- $6.9 billion aborted acquisition of Coherent, after public bidding war
- $1.8 billion acquisition of Oclaro
- Microchip in its $10.2 billion acquisition of Microsemi
- DoorDash in its $8 billion acquisition of Wolt Enterprises
- Pismo in its $1 billion acquisition by Visa
- MaxLinear in its aborted $3.8 billion acquisition of Silicon Motion
- Talend in its $2.4 billion acquisition by Thoma Bravo
- Gogoro in its $2.35 billion de-SPAC merger with Poema Global
- Pacific Biosciences in its $1.2 billion acquisition by Illumina (aborted)
- Neotract in its acquisition by Teleflex for up to $1.1 billion
- Microchip in its $3.6 billion acquisition of Atmel, after the termination of its existing transaction with Dialog Semiconductor
- HomeAway in its $3.9 billion acquisition by Expedia
- Microchip Technology in its $840 million acquisition of Micrel
- Integrated Silicon Solution Inc. (ISSI) in its $800 million acquisition by a Chinese investment group led by SummitView Capital, after a public bidding war with Cypress Semiconductor
- Omnivision in its pending $1.9 billion acquisition by an investment group led by Hua Capital
- Technicolor in its $600 million acquisition of Cisco's Connected Device Division
- Microchip Technology in its $940 million acquisition of Standard Microsystems Corp.
- Calistoga Pharmaceuticals in its acquisition by Gilead Sciences for up to $600 million
- Ardian in its acquisition by Medtronic for up to $1.5 billion
- Varian in its $1.5 billion acquisition by Agilent Technologies
- Acclarent in its $785 million acquisition by Ethicon (a Johnson & Johnson company)
- Wind River Systems in its $900 million acquisition by Intel
- CoreValve in its $775 million acquisition by Medtronic
- Francisco Partners in $720 million sale of Metrologic Instruments
- Google in multiple acquisitions
Recent Insights
Client Highlights
Wilson Sonsini Advises Rocket Lab on $8 Billion Acquisition of Iridium
On June 29, 2026, Rocket Lab Corporation, a global leader in launch and space systems, and Iridium Communications, a leading provider of global voice, data and positioning, navigation, and timing satellite services, announced they have entered into a definitive agreement under which Rocket Lab will acquire Iridium. Rocket Lab will acquire all the outstanding shares of Iridium common stock for $54 per share in a cash and stock transaction. This represents an enterprise value for Iridium of approximately $8 billion. Wilson Sonsini Goodrich & Rosati is advising Rocket Lab on the transaction.
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Bylined Articles
Law360 Article: “7 Key Questions About SEC’s Faster Tender Offer Path”
Wilson Sonsini attorneys Rob Ishii, Doug Schnell, Remi Korenblit, Tamara Brightwell, and Michael Anthony authored a recent Law360 article titled "7 Key Questions About SEC’s Faster Tender Offer Path." The piece examines the recent order issued by the SEC to shorten the minimum offering period on certain equity tender offers. The authors walk through seven key questions covering eligibility requirements, timeline implications, private company applicability, and strategic considerations—noting that while the shortened period offers meaningful efficiency gains, parties must carefully weigh trade-offs, including reduced time for boards to consider topping proposals and potential sequencing issues with go-shop periods.
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Recent Events
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M&A and Regulatory Considerations Under a Biden Administration
A new administration often brings significant changes to the regulatory environment and the Biden Administration will not be the exception. Areas to watch include antitrust, privacy and CFIUS issues arising in mergers and acquisitions involving technology and the biotech industries.
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