While the bill, passed late on May 20, imposes stricter regulations on Wall Street, major banks reacted positively to the reform's passage, and shares climbed on May 21.

Morgan Stanley (MS, Fortune 500) and JPMorgan Chase (JPM, Fortune 500) jumped nearly 6%, while Wells Fargo (WFC, Fortune 500) and Bank of America (BAC, Fortune 500) were up almost 5%. Goldman Sachs (GS, Fortune 500) and Citigroup (C, Fortune 500) rose significantly as well.

That's because, despite the tough regulations in the bill, including increased oversight of major banks and new rules for derivatives trading, the passage of the reform brought some clarity to the market, said Jeffrey Kleintop, chief market strategist at LPL Financial.