* Oil prices jump about 5 pct
* Gap sinks after poor March same-store sales
* Indexes up: Dow 0.55 pct, S&P 0.58 pct, Nasdaq 0.52 pct (Updates to open)
By Yashaswini Swamynathan and Abhiram Nandakumar
April 8 (Reuters) - Wall Street was higher on Friday, bolstered by a surge in crude oil and Federal Reserve Chair Janet Yellen's comments pointing to resilience in the U.S. economy.
U.S. crude rose 5 percent on rising hopes that top producers would agree to freeze output and economic indicators in the United States and Europe would push demand higher.
Yellen, in an appearance with former Fed chairmen on Thursday, said the U.S. economy was on a solid course with some hints of inflation, putting the central bank on track for a gradual increase in interest rates this year.
New York Fed President William Dudley said a cautious and gradual approach to raising rates was appropriate, given lingering external risks to the U.S. economy.
U.S. stocks have been volatile through the week, with the S&P 500 down 1.5 percent, as investors fretted over a cloudy outlook on rates and signs of weakness in the global economy.
Investors will look for improvement in fundamental factors, such as in upcoming corporate earnings, said Peter Cecchini, managing director and chief market strategist at Cantor Fitzgerald.
"In terms of sentiment, investors are pretty wary," he said.
Earnings at S&P 500 companies are seen to have declined 7.4 percent in the first quarter, according to Thomson Reuters data.
At 9:37 a.m. ET, the Dow Jones industrial average was up 96.02 points, or 0.55 percent, at 17,637.98, the S&P 500 was up 11.76 points, or 0.58 percent, at 2,053.67 and the Nasdaq Composite was up 25.37 points, or 0.52 percent, at 4,873.74.
All 10 major S&P sectors were higher, led by a 1.58 percent rise in the energy sector. Chevron shares rose 1.5 percent to $96.18.
Boeing was up 1.5 percent at $128.85, giving the biggest boost to the Dow. The company on Thursday said it had booked four orders for its 747-8 freighter, the first sales of the year for the plane.
Yahoo rose 1.4 percent to $36.65 after Re/code reported that the Internet company had extended the deadline to bid for its businesses by a week.
Gap shares were down 9.5 percent at $25.11 after the company's poor same-store sales for March prompted Citigroup to cut its price target on the stock.
Advancing issues outnumbered decliners on the NYSE by 2,395 to 324. On the Nasdaq, 1,668 issues rose and 559 fell.
The S&P 500 index showed five new 52-week highs and no new lows, while the Nasdaq recorded 11 new highs and four new lows. (Reporting by Yashaswini Swamynathan and Abhiram Nandakumar in Bengaluru; Editing by Anil D'Silva)