Earlier this year, the department told retirement plan sponsors they could face an "investigative program" if they allowed digital currencies in their workplace plans.

The biggest obstacle the Commission faces in proving insider trading is one of its own creation; its failure to provide the market with a clear picture of how the securities laws apply to digital assets will make it harder to prove that the tokens at issue qualify as "securities" under federal law.

"We expect the recent wave of pay transparency legislation to continue," says Mariann Madden, North America Fair Pay co-lead, WTW.

The company, as well as trustee GreatBanc Trust, caused the plan to overpay for company stock.