* Twitter rallies after blockbuster results
* GDP shows stronger economic growth than expected in Q2
* Biotechs rally, but insurers fall
* Dow down 0.4 pct, S&P down 0.1, Nasdaq up 0.3 pct
(Updates to midday trading)
By Ryan Vlastelica
NEW YORK, July 30 U.S. stocks were flat on
Wednesday, paring earlier gains as a strong read on
second-quarter economic growth sparked concerns the Federal
Reserve may adjust its stimulus earlier than expected.
Major indexes opened higher but lost their gains throughout
morning trading. While the Nasdaq remained in positive
territory, helped by biotech shares, the Dow was pressured by a
drop in insurer UnitedHealth Group Inc.
Gross domestic product grew at a 4 percent annual rate in
the second quarter, above the 3 percent rate that had been
expected and a sharp reversal from the weather-impacted first
quarter, when the economy contracted a revised 2.1 percent.
The data comes ahead of a statement from the Federal Open
Market Committee this afternoon, as the Fed concludes its latest
policy meeting. The central bank is widely expected to trim
monthly asset purchases to $25 billion from $35 billion, and
investors are looking for any hint on when officials could start
to reverse their monetary accommodation.
"The 4 percent number was startlingly good, and it has
increased anxieties that the Fed may change its policies," said
Mark Luschini, chief investment strategist at Janney Montgomery
Scott in Philadelphia.
"The report may not be enough to change today's statement,
but it comes after several datapoints suggesting things are
firming, which could mean the Fed can't be as passive as was
proposed in recent meetings."
Separately, the ADP National Employment Report showed
companies hired 218,000 workers in July, below analysts'
projections and less than June's total.
The Dow Jones industrial average fell 66.69 points or
0.39 percent, to 16,845.42, the S&P 500 lost 2.5 points
or 0.13 percent, to 1,967.45 and the Nasdaq Composite
added 11.98 points or 0.27 percent, to 4,454.68.
Biotechnology stocks boosted The Nasdaq for a second
straight day. The Nasdaq biotech index was up 1.8 percent
after Amgen Inc posted better-than-expected earnings
and raised its outlook, sending shares up 6 percent to $130.67.
Regeneron Pharmaceuticals Inc, jumped 9.8 percent
to $334.46 after reporting positive results from a Phase III
Insurance stocks fell after Humana Inc, WellPoint
Inc and Aflac Inc all reported lower earnings,
though WellPoint's profit was above expectations.
Humana fell 6.3 percent to $119.49, WellPoint lost 2.2
percent to $110.02 and Aflac slid 3.8 percent to $60.72.
UnitedHealth lost 2.9 percent to $81.85 as the Dow's biggest
Fellow Dow component American Express Co reported
adjusted earnings in line with expectations; shares fell 1.3
percent to $90.52.
On the upside, Twitter Inc surged 21 percent to
$48.25, its biggest ever one-day advance, after reporting
monthly active users rose a better-than-expected 24 percent in
the second quarter.
The results bolstered support for other social media stocks.
Facebook Inc rose 1.8 percent to $75 while LinkedIn Corp
rose 3.6 percent to $186.26.
While this earnings season has been positive in aggregate,
with more companies than usual beating expectations for both
earnings and revenue, there have been some high-profile
disappointments from UPS and Amazon.com Inc.
(Editing by Nick Zieminski)