Western Digital jumped nearly 10 percent as one of the greatest advancers in the Nasdaq. The firm reported adjusted quarterly profit that topped estimates but the hard drive maker's revenue was below forecasts.
On the other hand, Facebook fell about 2 percent to weigh on the Nasdaq as investors were disappointed by an 82 percent surge in expenses. The social media giant did report earnings after the close Wednesday that beat on both the top and bottom line.
"Overall I think the Facebook numbers reflect tremendous strength in their business," said Steve Weinstein, senior research analyst at ITG Investment Research. "I don't see anything in their numbers that will change the trajectory of their business. I think the selloff today is not material."
Other firms reporting earnings before the bell were Cigna and AB InBev. Companies posting results after the close include Amgen,LinkedIn and Expedia.
"I think earnings have been very enlightening this quarter, and the market is starting to get the message that things aren't as good as previously thought," said Maris Ogg, president at Tower Bridge Advisors.
Insurance company Cigna posted mixed quarterly results. Brewer AB InBev missed on both the top and bottom line due to poor weather and weak economic conditions.
"I think what's driving markets here is earnings and we've been up two days in a row," said Art Hogan, chief market strategist at Wunderlich Securities.
"The Fed has come and gone in the July time frame such that consensus hasn't moved an inch. Everybody's trying to come up with a reason why the Fed shouldn't raise rates," he said. "Pick your poison but the Fed really is trying desperately for one if not two rate hikes."
In economic news, U.S. gross domestic product came in at 2.3 percent, slightly below economists' estimates. The department revised its first-quarter GDP reading to a 0.6 percent increase from a 0.2 percent contraction.
"I was mostly surprised by the first quarter revision in GDP," said Randy Frederick, managing director of trading and derivatives at Charles Schwab.
"This means there are no negative quarters, and that's good," he said.
Read MoreUS government revises earlier GDPs to fix anomalies
"I think this means (policymakers) have room to hold off on an interest rate hike," said Tara Sinclair, chief economist at Indeed.
Sinclair remains optimistic on the economy despite the miss on the second-quarter growth figure. "My own reading of the data is there's still room to grow," she said.
U.S. weekly jobless claims increased by 12,000 week-over-week, but came in below expectations at 267,000, the Labor Department said.
"The thing with GDP is that it's old news. We're already well into the third quarter and this is a far back looking number," said Peter Boockvar, chief market analyst at The Lindsey Group. He added that Wall Street was "more focused on digesting what the Fed said yesterday."
On Wednesday, the central bank kept rates unchanged and gave no hint of liftoff coming in the next meeting. The decision on the rates was unanimous. Policymakers said the economy is expanding moderately and made no mention of recent volatility around Greece or China.
"While the official estimates say December is now more likely (for a rate hike), I believe most investors think September is the more likely bet," Frederick said.
In fact, Mark Luschini, chief investment strategist at Janney Montgomery Scott, noted that the one of the Fed's favorite indicators on inflation, the core personal consumption expenditures price index, rose 1.8 percent.
Read MoreUS GDP a dud but gives Fed inflation glimmer it needs
Not all analysts were convinced the economic data supports a rate hike in September.
"I think the underlying takeaway today is the Fed is facing a real problem," said Adam Sarhan, CEO of Sarhan Capital. "How can the Fed justify their word if economic growth is coming in lower than expected, with rates at zero?"
The Dow Jones industrial average closed down 5.41 points, or 0.03 percent, at 17,745.98, with Procter & Gamble leading decliners and Microsoft the greatest advancer.
The S&P 500 closed up 0.06 points, or 0.00 percent, at 2,108.63, with energy leading four sectors lower and utilities the greatest advancer.
The Nasdaq closed up 17.05 points, or 0.33 percent, at 5,128.78.
The CBOE Volatility Index (VIX), widely considered the best gauge of fear in the market, traded near 12.
Advancers were a touch ahead of decliners on the New York Stock Exchange, with an exchange volume of 789 million and a composite volume of 3.5 billion in the close.
The U.S. dollar traded about half a percent higher against major world currencies, with the euro at $1.09.
The 10-year Treasury yield fell to 2.26 percent, while the 2-year note yield trimmed gains to hold near 0.73 percent.
Treasury Department auctioned $29 billion of 7-year notes at a high yield of 2.021 percent.
Crude oil futures for September delivery settled down 27 cents at $48.52 a barrel on the New York Mercantile Exchange. Gold futures settled down $4.60 at $1,088.70 an ounce.
—CNBC's Peter Schacknow contributed to this report.
On tap this week:
Earnings: Amgen, Broadcom, Digital Realty Trust, Electronic Arts, Expedia, LinkedIn, United Health Services, Western Union, FireEye, Tempur Sealy
Earnings: Exxon Mobil, Chevron, Honda Motors, Seagate Technology, TransCanada, Newell Rubbermaid, Weyerhaeuser, Phillip 66, CBOE Holdings, Legg Mason, ArcelorMittal
8:30 am: Employment cost index
9:45 am: PMI
10:00 am: Consumer sentiment
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