People working for the U.S. Securities and Exchange Commission (SEC) who owned stock in companies under investigation were more likely to sell shares than other investors in the months before the agency announced it was taking enforcement actions, according to a new academic paper.

SEC employees holding shares of five firms, including JPMorgan Chase & Co. and General Electric Co., in 2010 and 2011 sold stock in 62 percent of the trades they initiated, compared with 50 percent among all the investors who traded those shares in that period, Emory University accounting professor Shivaram Rajgopal reports in the paper.

Rajgopal, who plans to present the work today at a University of Virginia accounting seminar, said in a telephone interview that while the analysis doesn't prove misconduct, it points out a suspicious pattern.