Citadel, run by Ken Griffin out of Chicago, reported $115.2 billion of regulatory assets in a March 30 filing with the U.S. Securities and ExchangeCommission, compared with $12.6 billion of net assets. Millennium, founded by Israel Englander, disclosed comparable figures of $119 billion and $13.5 billion as of year-end.

The two firms are among more than 1,200 private fund advisers that have registered this year with the SEC and begun providing a more comprehensive count on the assets they manage, including those acquired through the use of borrowed money, under rules aimed at curbing systemic financial market risks. The filings, which regulators may use to identify firms they want to monitor more closely, suggest the largest funds have returned to the level of leverage used before the financial crisis. […]