The Nasdaq composite held mildly lower as Facebook traded more than 2.5 percent lower and the iShares Nasdaq Biotechnology ETF (IBB) briefly declined more than 1.5 percent.  The Dow Jones industrial average traded about 40 points higher after earlier adding more than 150 points. UnitedHealth and Nike were the greatest contributors to declines in the Dow, while Boeing and Chevron were the top contributor to gains.  Traders also noted some pressure on stocks after several downward revisions to first-quarter GDP estimates following wholesale inventories' 0.5 percent decline in February, the sharpest decline since May 2013, Reuters reported.  The Atlanta Fed's GDPNow model said the U.S. economy was on track to grow 0.1 percent in the first quarter, down from the previous 0.4 percent estimate.  WTI held gains, surging more than 6.5 percent to near $39.80 a barrel in midday trade, ahead of the oil rig count due in the afternoon. U.S. crude oil futures are on pace for a weekly gain of more than 7.5 percent.  "The fact oil's up more than 5 percent today and it's being defended for the week helps the risk-on crowd pile into stocks," said Adam Sarhan, CEO of Sarhan Capital.  The Dow transports briefly jumped more than 2 percent, on pace to snap a six-day losing streak, while the Russell 2000 was up about a third of a percent after earlier rising 1 percent. Both indexes are still on pace for a weekly loss of more than 1 percent.  "I think the Fed (speakers) are basically just comforting to the market," said Peter Cardillo, chief market economist at First Standard Financial.  In a panel discussion with three former Fed chairs late Thursday, Fed Chair Janet Yellen said she "certainly wouldn't describe this as a bubble economy."  "That's basically flashing a green light for investors," Cardillo said, noting the comments could be interpreted as indicating fair valuation in stocks and no potential recession in the U.S. economy.  Read More This is what could create some turbulence Friday  Early Friday morning New York Fed President William Dudley said a cautious, gradual approach to rate hikes is appropriate. He noted lingering external risks to the U.S. economy, despite some strength and signs of inflation domestically.  The Fed comments helped support a risk-on tone in markets in morning trade.  Gold traded mildly lower before turning higher in midday trade. Treasury yields edged higher.  The 2-year Treasury yield was near 0.70 percent and the 10-year yield around 1.72 percent as of 12:27 p.m. ET.  U.S. stocks closed lower Thursday, with the Dow losing 174 points. Stocks gained Wednesday, following the first triple-digit decline in the Dow since March 8 on Tuesday.  As of morning trade Friday, the major U.S. averages were on pace for a weekly decline of just under 1 percent. The S&P 500 and Dow held higher for the year so far.  "The vehemence of the bounce after very, very small pullbacks in the price that shows ... buyers remain under the market for now," Sarhan said.
U.S. stocks traded mixed Friday, amid a rally in oil prices, as the yen held near highs not seen against the U.S. dollar since October 2014.