* Second reading of Q1 GDP at 0.8 pct vs. 0.9 pct est.
* Yellen to speak at 1:15 p.m. ET
* GameStop drops after forecast falls short of expectations
* Ulta Salon jumps after raising full-year forecast
* Futures up: Dow 17 pts, S&P 1.75 pts, Nasdaq 6.5 pts (Adds details, comment, updates prices)
By Tanya Agrawal
May 27 (Reuters) - Wall Street was set to open little changed on Friday as cautious investors braced for a speech by Federal Reserve Chair Janet Yellen for further clues on the timing of interest rate hikes.
Yellen is due to speak at an event hosted by Harvard University at 1:15 p.m. ET (1715 GMT). Her speech comes after a number of Fed policymakers this week struck hawkish tones on the trajectory of interest rates.
Investors have grown more comfortable with expectations that the central bank could raise rates as soon as June, with many taking the view that such a hike would reflect improvement in the country's economy.
A rate hike in June was seen as highly unlikely until recently. However, the Fed funds futures are now pricing in a 25 percent chance of a rate hike in June and 45 percent in July after a string of strong data and comments from policymakers.
The Fed next meets on June 14-15.
"We're expecting a lot of major data in the next few weeks and Yellen will balance her comments keeping that in view," said Nadia Lovell, U.S. equity specialist at J.P. Morgan Private Bank in New York.
"Our view is that we will get two rate hikes this year. June doesn't seem likely with the British referendum but with housing data coming in strong and unemployment continuing to improve, July seems likely, with another one post-election in December."
S&P 500 e-minis were up 1.75 points, or 0.08 percent, with 107,110 contracts traded at 8:36 a.m. ET. Nasdaq 100 e-minis were up 6.5 points, or 0.14 percent, on volume of 16,111 contracts. Dow e-minis were up 17 points, or 0.1 percent, with 14,077 contracts changing hands.
Data on Friday showed the U.S. economic growth slowed in the first quarter although not as sharply as initially thought.
Gross domestic product rose at a 0.8 percent annual rate as opposed to the 0.5 percent pace reported last month - the slowest growth since the first quarter of 2015. Economists polled by Reuters expected a 0.9 percent growth rate.
The University of Michigan's final consumer sentiment index likely cooled a bit to 95.4 in May from a preliminary reading of 95.8 earlier this month. That data is expected at 10 a.m. ET.
Wall Street closed mostly flat on Thursday as investors took a breather following two days of strong gains.
Shares of cyber security firm Palo Alto were down 10.2 percent at $133.12 in premarket trading after posting a wider-than-expected quarterly loss.
GameStop fell 5.9 percent to $28.19 after the video-game retailer forecast lower-than-expected revenue and profit for the current quarter.
U.S-listed shares of Valeant Pharmaceuticals were up 8 percent at $29.14 after sources said the drugmaker rejected a joint takeover offer from Japan's Takeda Pharmaceutical and TPG Capital Management.
Ulta Salon Cosmetics and Fragrance was up 8.5 percent at $231.75 after the beauty product retailer raised its full-year forecast. (Reporting by Tanya Agrawal; Editing by Anil D'Silva)