US STOCKS-Wall St rises as Yellen says case for rate hike stronger
* Yellen says case for rate hike has strengthened
* Financials stocks surge, led by banks
* Herbalife drops on report of Icahn's planned stake sale
* Indexes up: Dow 0.57 pct, S&P 0.64 pct, Nasdaq 0.73 pct (Adds details, comments, updates price)
By Yashaswini Swamynathan
Aug 26 (Reuters) - Wall Street was higher on Friday morning after Federal Reserve Chair Janet Yellen said the case for raising U.S. interest rates has strengthened in recent months.
Yellen, speaking before a gathering of global central bankers in Jackson Hole, Wyoming, did not indicate when the Fed would raise rates, but said the central bank thinks future hikes should be "gradual".
"In light of the continued solid performance of the labor market and our outlook for economic activity and inflation, I believe the case for an increase in the federal funds rate has strengthened in recent months," Yellen said in prepared remarks.
All 10 major S&P 500 sectors were higher. Financials , which stand to gain the most if rates are raised, jumped 0.78 percent. Continuación...