Simpson Thacher & Bartlett
Elite New York law firm advising on mega M&A deals and private equity funds.
On the record
Checkpoint: Am Law 200 2027 rankings show if H1 2026 M&A slippage reverses
The call
Revenue and profit keep climbing while rivals pull ahead in M&A and PE league tables, leaving its lead position genuinely contested.
Simpson Thacher is a major law firm that handles big business deals, especially helping private equity firms buy companies. It has long-standing relationships with huge clients like KKR and Alibaba, plus a legal advantage because regulators require top lawyers to sign off on massive transactions, which AI cannot yet replace. However, competitors like Kirkland and Latham have been winning more of Simpson Thacher's traditional private equity work in recent years, and the firm is no longer ranked as a top player in that area. The biggest threat ahead is whether AI tools that draft legal documents will let clients refuse to pay high rates for associate work, which could squeeze the firm's profits if partners cannot raise prices fast enough to offset the lost billable hours.
Why
01
AI pressure: Harvey and DeepJudge AI drafting and review tools. AI drafts first-pass contracts cheaper, squeezing the billable-hour training pyramid under partners. Could AI do the core job? Unlikely.
02
Bigger players: Kirkland & Ellis and Latham & Watkins. Kirkland and Latham now out-lead Simpson Thacher in M&A deal volume and private equity matter counts. Could a giant copy it? Probably.
03
What protects it. Clients still need a named partner's liability signoff on mega-deals, something no AI tool can give.
What would change this call
Am Law 2027 rankings (April 2027) show STB's M&A/PE league-table position. Confirms whether the H1 2026 slippage behind Kirkland, Latham, Skadden persists or reverses.
Resolution of the Aramark professional negligence matter (claim filed, settled, or dropped). Tests whether liability exposure escalates into a material reputational or client-flight event.
Any further Microsoft-style client matters withdrawn over political/deal scrutiny in 2026-2027. Would show political controversy is actively driving client defection, not just reputational noise.
Resolution of the Aramark professional negligence matter (claim filed, settled, or dropped). Tests whether liability exposure escalates into a material reputational or client-flight event.
Any further Microsoft-style client matters withdrawn over political/deal scrutiny in 2026-2027. Would show political controversy is actively driving client defection, not just reputational noise.
Key numbers
- $3.55B revenue, up 22.7% YoY
- PEP $8.57M, ranks 8th in Am Law 100
- Kirkland $743.3B M&A 2025 vs STB 5th place
Named risks
- UK tribunal flagged possible professional negligence claim over Aramark CMA deadline error, 2026-03.
- Slipping out of M&A/PE top tier in H1 2026 versus Kirkland, Latham, Wachtell, Skadden.
- Political backlash from $125M Trump pro bono deal risking further client defections beyond Microsoft's partial pullback.
- Departure of AI strategy lead Andrew Baker to Entegrata in July 2026 raises continuity concerns for AI program.
- Profit-pyramid strain: nonequity partners growing 33.4% YoY vs equity partners 3.2%, exposed to AI eroding billable leverage.
Rivals, as read in July 2026
| Rival | Direction | Evidence |
|---|---|---|
| Kirkland & Ellis | gaining on | Led H1 2026 global M&A with $474.5B across 350 deals; STB absent from top tier, 2026-07-08 |
| Latham & Watkins | gaining on | Led 2025 global M&A with $786.7B vs Simpson Thacher's $403B, 2025 full-year data |
| Wachtell Lipton | gaining on | PEP of $12.15M in 2026 vs Simpson Thacher's $8.57M |
| Skadden Arps | gaining on | $402.8B in H1 2026 M&A, ranked ahead of Simpson Thacher which was absent from top tier |
| Jenner & Block | contesting | Replaced Simpson Thacher on Microsoft's Activision Blizzard shareholder matter, 2025-05-01 |
Questions people ask
- Is Simpson Thacher & Bartlett profitable?
- Yes. FY2025 gross revenue hit $3.55 billion, up 22.66% year over year, while profits per equity partner (PEP) rose 11.8% to $8.57 million, the 8th highest in the Am Law 100, per Law.com data published 2026-04-06.
- Could AI replace Simpson Thacher's lawyers?
- Unlikely soon. The firm's core value is liability-bearing counsel-of-record status on mega-deals, which AI cannot assume. It uses Harvey and DeepJudge internally, but industry-wide lawyer AI adoption is only about 19% as of 2025-2026, per Clio.
- Who is Simpson Thacher's biggest competitor?
- Kirkland & Ellis. Kirkland led H1 2026 global M&A with $474.5 billion across 350 deals (2026-07-08), and Simpson Thacher, once dominant in private equity, did not appear in that period's reported top tier.
- Who owns Simpson Thacher & Bartlett?
- It is a private law partnership owned by its partners, with 204+ equity partners and 111 nonequity partners as of 2025 (nonequity ranks up 33.4% year over year). There are no external investors or parent company, per firm-reported American Lawyer data.
- Did Simpson Thacher lose Microsoft as a client?
- Partially. Microsoft removed Simpson Thacher from a Delaware Chancery Court Activision Blizzard shareholder suit in favor of Jenner & Block around 2025-05-01, within two weeks of the firm's Trump pro bono deal, though Microsoft said the firm continues on other matters.
- Is Simpson Thacher facing a malpractice or negligence claim?
- A UK tribunal flagged the possibility. In March 2026, the Competition Appeal Tribunal refused to extend a deadline after Simpson Thacher misinterpreted appeal rules, costing client Aramark its chance to challenge a CMA divestment order, and raised the prospect of a professional negligence claim.
Timeline
- 2026-07-23AI lead Andrew Baker departs Simpson Thacher for legal-data startup Entegrata
- 2026-07-08Kirkland tops H1 2026 global M&A rankings; Simpson Thacher absent from top tier
- 2026-06-01Finalizes ~916,000 sq ft lease at Extell's 570 Fifth Avenue, Manhattan
- 2026-04-06Reports FY2025 revenue of $3.55B (+22.66%) and PEP of $8.57M (+11.8%)
- 2026-03-11UK tribunal flags possible negligence claim after Aramark deadline blunder
- 2026-01-05Opens new San Francisco office in former Google space
- 2025-12-15Promotes record 59 lawyers to partner, up from 44 prior year
- 2025-11-05Expands Boston Winthrop Center lease for 10-year term
- 2025-05-01Microsoft removes firm from Activision Blizzard shareholder matter
- 2025-04Agrees to $125M pro bono deal with Trump administration
Revision history
23 July 2026
First assessed. Defensible for now. The text above is fixed as of this date and is not edited afterwards.
In the same band
Sources
- Simpson Thacher Crosses $7.5M in PEP, Revenue Jumps 24% (2025-04-03)
- Simpson's Revenue and Profits Surge, Amid Rapid Partnership Expansion (2026-04-06)
- Simpson Thacher appoints 59 to partnership in record promotions round (2025-12-15)
- American Lawyer reprint (2025-04-03)
- Latham Tops Kirkland for M&A Crown in Year Marked by Megadeals (2026-01-02)
- Kirkland tops global M&A rankings after strongest first half for dealmaking since records began (2026-07-08)
- The $12 Million Partner Era and the 2026 BigLaw PEP Rankings (2026-06-01)
- Who's Building, Who's Bleeding, and Why BigLaw May Be PE's Next Acquisition Target (2026-06-03)
- Simpson Thacher & Bartlett, Law Firm Profile
- How many employees work at Simpson Thacher? (2025-12-29)
- Simpson Thacher Fulfills Boston Promises with New Space, Hires (2025-11-05)
- Simpson Thacher Expands Bay Area Presence with New San Francisco Office (2026-01-05)