Wall Street banks get a boost on Yellen comments

Wall Street banks got a shot in the arm Friday when Federal Reserve Chair Janet Yellen suggested that an interest rate hike could be coming sooner rather than later.

"I believe the case for an increase in the federal funds rate has strengthened in recent months," Yellen said in her prepared remarks in Jackson Hole, Wyoming.

Especially for the biggest consumer banks in the U.S., that is big news. Most Wall Street banks, including JPMorgan Chase (JPM), Bank of America (BAC) and Citigroup (NYSE:C), saw shares rise after the text of Yellen's speech was released.

"The largest banks should benefit right away from any language about increasing rates in 2016," said Erik Oja, U.S. banks analyst with S&P Global Market Intelligence.

Especially for the biggest consumer banks in the U.S., a near-term rate hike might prove crucial to preserving their margin. Wall Street banks have struggled to offset diminished revenue on key products like mortgages, where they have earned little in the lower-for-longer environment.

However, banks with limited or developing consumer businesses also got a lift on Yellen's comments. Morgan Stanley (MS) and Goldman Sachs (GS) stock also rose Friday morning. Even some of Wall Street's smaller banks saw stock rise on the news.

Another expert cautioned that a rate hike may not be coming as soon as some might hope.

"Financials are enjoying the prospect of a rate hike in the coming months, but so are utilities moving on the prospect that rates won't be lifted at the September Fed meeting," said Quincy Krosby, market strategist at Prudential Financial. Gold is moving higher as well, again signaling that while rates may be lifted it's not a September story."

- CNBC finance editor Jeff Cox contributed to this story.