 Members of Congress and their family members are supposed to disclose their trades within 45 days. Now there are funds you and I can invest in that use that information to mimic congressional trades. One ETF tracking the trades of congressional Democrats has gained 30 percent since it was started in February of last year, beating the S&P, according to Yahoo Finance. Eric Gordon, a professor at the University of Michigan Ross School of Business, looked at what's behind the success of congressional stock picking campaigns.