NEW YORK ( TheStreet) -- Financial stocks were higher nearly across the board Wednesday, outpacing the broader market. The Financial Sector SPDR ( XLF), a popular exchange traded fund that tracks financials stocks, rose 0.80% to close at $16.45. Visa ( V - Get Report) was one of the big winners, as the Federal Reserve missed an April 21 deadline for issuing final rules placing restrictions on debit interchange fees that banks and debit card companies charge to merchants. Shares of Visa rose 2.81% to $74.23 on more than double their average volume. MasterCard ( MA - Get Report) shares also rose on twice their average volumes, though the gains were a more modest 0.77% to $253.66. A report Wednesday from Keefe, Bruyette and Woods argued the delay was "a positive for Visa and MasterCard as a delay could be perceived as the Fed considering some alternate scenarios that may be less onerous than the initial proposals." Shares of Discover Financial Services ( DFS - Get Report) and American Express ( AXP - Get Report)were also higher, with Discover up 2% to $24.98 on better-than-average volumes and Amex rising 0.57% to $45.91 on light volumes. Sandler O'Neill analyst Mike Taiano says these companies will not be greatly harmed by the interchange fee rules and Discover may even see a benefit. He attributes Discover's gains on Wednesday to ongoing investor excitement about the company's ability to generate capital strength. Discover shares have risen 12% over the past month while the S&P 500 has posted a slight decline. BlackRock ( BLK - Get Report) was another big gainer--its shares rising 6.62% on more than six times their average volumes on news the stock will join the S&P 500 after Friday's close. Derek Pilecki, portfolio manager with Gator Capital Management, has been short BlackRock, a position that had been working until he was caught off guard by the S&P/BlackRock announcement. "It's a technical thing that's hard to anticipate, but I'm going to hand in there," Pilecki says. Central to his bearish thesis on BlackRock is that the money manager's exchange-traded fund business will suffer due to competition from Vanguard. -- Written by Dan Freed in New York.