Evidence since late 2023 shows some headwinds for tech/startup M&A and exits, but they are driven by several overlapping forces (rates, valuation reset, weak IPO window, and broader regulatory pressure), and it’s not possible to cleanly attribute a distinct, regulator‑caused “chilling effect” of the kind Sacks describes, nor to isolate its impact on risk capital.

Key points:

1. Tech and broader M&A volumes fell, but values rebounded and activity is now rising again.

   • PwC reports that in 2024 global TMT (tech/media/telecom) deal volumes were 27% below 2023, and technology deal volume specifically declined 29% year‑on‑year, even as technology deal values rose 33%, driven by fewer but larger software deals. Explanations emphasize macro factors (rates, valuation gaps) rather than regulation as the primary driver. (pwc.com)
   • Across all sectors, 2024 global M&A deal values increased about 5–10%, while deal counts fell roughly 14–17% versus 2023, again framed mainly as a consequence of higher interest rates, valuation mismatches, and PE constraints rather than a primarily regulatory story. (pwc.com)
   • By late 2024 and into 2025, several analyses (Bain, PwC, Barron’s) describe M&A as rebounding: overall deal value in 2024 is up mid‑teens percent vs 2023, deal volume up modestly, and 2025 year‑to‑date M&A value is surging, with large contributions from technology and AI deals. This is not consistent with a sustained, system‑wide freeze in M&A. (bain.com)

2. Startup exits are weak, but they were already depressed and are mainly tied to macro and valuation resets.

   • Carta’s data show startup M&A transactions in its universe fell 11% in 2023 vs 2022; IPO activity remained at historically low levels after the 2021 boom. The commentary frames the “IPO chill” and exit slowdown primarily in terms of the post‑2021 bust and market conditions, not competition policy. (carta.com)
   • PitchBook’s 2024/2025 analyses describe the startup exit market as “pretty stuck,” with LP liquidity back to global‑financial‑crisis‑era levels and many bridge/insider rounds, again pointing to valuation overhang and macro uncertainty as central issues. (techcrunch.com)
   • These trends began well before December 2023, and continue through 2024–25; they are clearly consistent with “fewer good exits,” but they are not uniquely or even primarily attributed to agencies like the CMA.

3. Regulators have increased scrutiny and some practitioners explicitly talk about a chilling effect—but aggregate data say deals are still getting done.

   • In the U.S., antitrust lawyers and deal advisors describe the FTC/DOJ’s novel merger guidelines and aggressive posture as having a “chilling effect” and raising the “merger tax” (greater time, cost, and uncertainty). Sellers sometimes accept lower‑priced bids with cleaner antitrust profiles, indicating real friction from enforcement. (dailyjournal.com)
   • Policy and advocacy pieces (e.g., NYU Law Review commentary summarized by PULSE) argue that expanded merger review requirements and a perception that acquisitions by incumbents are risky reduce the appeal of exiting by acquisition, and may therefore reduce capital flowing into the startup sector—a mechanism very close to what Sacks describes. However, these are largely theoretical or qualitative arguments, not clean causal measurements. (pulseforinnovation.org)
   • At the same time, hard data from the U.S. HSR (merger notification) report show that while second‑request investigations and enforcement intensity have risen, overall M&A filing levels in 2024–2025 are close to or above 2023, and Reuters notes that stricter review “has not significantly deterred dealmaking,” even if it increases the chance of extended investigations. (reuters.com)

4. CMA‑specific behavior is mixed, and recently has shifted away from the posture Sacks worried about.

   • The UK CMA’s tough stance did help sink high‑profile deals like Adobe–Figma, which was abandoned in December 2023 after UK and EU antitrust concerns about future competition—an example of exactly the kind of subjective, future‑competition theory Sacks criticized. (theguardian.com)
   • But by 2024–2025, the CMA is under strong political pressure to support economic growth. Its leadership has publicly committed to a more “pro‑growth” approach, stated it will scrutinize fewer global deals, and has streamlined consultation timelines. The authority also dropped a formal probe into Microsoft’s partnership with OpenAI, a major AI/tech relationship. (ft.com)
   • This evolution undercuts the specific conditional in Sacks’s prediction (that regulators continue in the same slow, expansive direction); in practice, at least in the UK, the political system has pushed the CMA to moderate rather than double down.

5. The link to “less risk capital” is debated and not empirically nailed down.

   • VC activity is clearly below 2021’s peak, and down‑rounds and lower IPO valuations are widespread in 2024–2025, but most analyses cite the interest‑rate regime and valuation reset as the dominant explanations. (fortune.com)
   • Academic work on antitrust and VC is mixed. For example, one 2023 paper finds that reductions in local DOJ antitrust enforcement actually reduced VC investment and successful exits, implying that at least some enforcement can support venture ecosystems by constraining incumbents’ anticompetitive conduct—essentially the opposite of Sacks’s argument that tougher enforcement necessarily chokes off risk capital. (arxiv.org)

Why this is “ambiguous” rather than clearly right or wrong:

• Parts of Sacks’s causal story are superficially consistent with what we see: regulators did block or derail some marquee tech deals (e.g., Adobe–Figma, earlier phases of Microsoft–Activision), practitioners and commentators talk about a “chilling effect” and higher merger‑process friction, startup exits and VC‑backed liquidity are indeed weak, and some policy analyses explicitly warn that making M&A exits more uncertain can depress startup investment. (theguardian.com)
• However, macro factors and the post‑2021 valuation bust are clearly the primary, measurable drivers of the downturn in exits and funding. Global M&A and tech M&A have rebounded in value and are growing again by 2024–2025, even under heightened scrutiny, suggesting no decisive, sustained collapse of M&A activity. (pwc.com)
• CMA‑style regulators have not unambiguously “continued” along the exact path Sacks criticized; in the UK especially, the trend since 2024 is toward somewhat more pro‑growth, selective enforcement rather than ever‑expanding, slow, subjective review of tech M&A. (ft.com)
• Finally, the empirical literature on antitrust and VC is not one‑sided; there is no robust consensus that stricter merger enforcement in tech has, in net, reduced risk capital.

Given this mix, the available evidence does not allow a clean judgment that Sacks’s prediction has either clearly come true or clearly failed. The environment is more nuanced: regulatory scrutiny has introduced friction and some chilling at the margin, but broader data show M&A and capital flows recovering under multiple influences. Hence the classification as "ambiguous."