What it takes to break a deal and how boards should prepare
2026 report
Deals in Dispute: Activism Against M&A
What’s in this report from Diligent Market Intelligence and Seward & Kissel:
Contested M&A is no longer a niche concern. A new report from Diligent Market Intelligence, produced in association with Seward & Kissel, examines nearly 300 activist demands opposing the sale of US-listed companies since 2015, drawing on Diligent’s activism, voting and governance datasets. Opposition to announced deals has become a more durable feature of the public-company landscape, with activist success rates reaching their highest level in 2025 since 2018.
Some key findings:
- Proxy advisor recommendations remain a significant factor in contested deals, with the average vote in favor of an opposed merger varying dramatically depending on whether ISS recommended for or against.
- CEO tenure at target companies correlates with campaign outcomes, with oppose-sale demands proving considerably more likely to succeed against companies with shorter-tenured chief executives.
- Occasional activists accounted for the majority of oppose-sale demands examined and achieved at least partial success at a rate comparable to more established firms.