A new study by Cornerstone Research shows that plaintiff lawyers challenged 96% of all public-company mergers and acquisitions worth more than $500 million last year, lobbing an average of 5.4 suits per merger and suing an average of two weeks after each one was announced.
It’s not plausible that directors violated their duties to investors in virtually every large merger last year, said Robert Daines of Stanford Law School, a co-author of the report. Many of the suits were obviously without...