Melissa Sawyer, Sullivan & Cromwell's Global Head of M&A, says IPO market volume will be the key signal that M&A is truly recovering. She argues that once private equity sponsors feel confident enough to exit portfolio companies and recycle capital, a wave of M&A could follow. Sawyer also notes that a softer tone from Washington and US regulators' willingness to accept behavioral or divestment remedies have restored deal confidence, though the US regulatory thaw is not matched globally, creating cross-border deal challenges.