Many fund managers strive to be transparent with their financial disclosures. Others are so obstructive that they might as well be kicking sand in investors’ faces.

While private equity is synonymous with opacity, the tricks of the trade are taking on greater importance as the industry seeks to broaden its reach among ordinary investors. President Trump last week signed an order seeking to open up Americans’ 401(k) retirement accounts to private equity and other alternative investments. Rep. Elise Stefanik (R., N.Y.) made headlines when she asked the Securities and Exchange Commission in June to investigate the way Harvard is valuing its private-equity holdings.