Some billionaire investors are adopting a new tactic against recalcitrant creditors and shareholders: accusing them of illegal ganging up. Patrick Drahi was an early adopter, suing bondholders in the company formerly called Altice USA, now renamed Optimum Communications. Creditors including Apollo and Black Rock had formed a pact to negotiate a balance-sheet restructuring, which Optimum claimed was a restraint of trade.

Hollywood super-agent Ari Emanuel is doing something similar. He and backers at private equity firm Silver Lake accused investor Carl Icahn and dozens of other funds of illegal anti-competitive conduct. The company, media conglomerate Endeavor, now renamed WME Group, was taken private for $13bn in 2025. Endeavor says shareholders bought shares "in concert" and the court should dismiss their claims.

For buy-side investors, joining forces is appealing. During Donald Trump’s administration, law has swung in favor of companies, emboldening them to try such claims despite high legal bars. Investors in the Endeavor case are disgruntled because a prize asset—a stake in the owner of Ultimate Fighting Championship—soared after the take-private was announced, but public shareholders, denied a vote, were stuck with an outdated price.

Investors are pursuing appraisal rights to force more money, which could be costly for Emanuel. They claim a loftier principle of price discovery, but the real question is whether Endeavor’s board allowed the company to go private too cheaply. This could set a precedent and deserves court scrutiny. If Emanuel has a strong case, he should agree.