* S&P posts best two-day run in more than two months
* U.S. jobless claims drop to two-month low
* Amazon.com hits all-time high on analyst report
* Indexes up: Dow 0.54 pct, S&P 0.65 pct, Nasdaq 0.84 pct (Updates with close of U.S. markets)
By Lewis Krauskopf
Sept 22 (Reuters) - U.S. stocks climbed on Thursday, with big tech names leading broad gains, building on strength from a day earlier that was fueled by the Federal Reserve's decision to stand pat on interest rates.
The S&P 500 tallied its best two-day performance in more than two months, while the Nasdaq closed at a record high.
Fed Chair Janet Yellen said on Wednesday that U.S. growth was looking stronger and rate increases would be needed to keep the economy from overheating and fueling high inflation. But the central bank maintained the low-interest rate environment that has helped underpin the bull market for stocks.
"Lower for longer is a good thing for the equity markets..." said Paul Nolte, portfolio manager at Kingsview Asset Management in Chicago. "It basically says risk back on."
The Dow Jones industrial average rose 98.76 points, or 0.54 percent, to 18,392.46, the S&P 500 gained 14.06 points, or 0.65 percent, to 2,177.18 and the Nasdaq Composite added 44.34 points, or 0.84 percent, to 5,339.52.
The three indexes recorded their third straight session of gains.
Concerns over whether the Fed would raise rates prompted a return of stock market volatility in recent weeks after two months of calm. For the year, the benchmark S&P 500 is up 6.5 percent.
Aside from the potential for Monday's U.S. presidential debate having a big impact on the election, "there's really nothing on the horizon until earnings season, and the Fed has kind of cleared the way for accommodative policy and low interest rate environment which bodes well for stocks," said Alan Lancz, president of investment advisory firm Alan B. Lancz & Associates in Toledo, Ohio.
The Fed strongly signaled it could still tighten monetary policy by year-end, and as of Thursday afternoon traders set the probability of a hike at the Fed's December meeting at 58 percent, according to the CME Group's FedWatch website.
Adding some support for the Fed to raise rates later this year, a report showed number of Americans filing for unemployment benefits unexpectedly fell last week to a two-month low.
All 11 major S&P sectors closed in positive territory, led by a 1.9-percent gain for the real estate sector.
Shares of Amazon.com rose 1.9 percent to close above $800 for the first time following a price target raise by BMO. Apple shares gained 0.9 percent after positive analyst reports. The stocks were the biggest positive influences on the S&P.
About 6.8 billion shares changed hands on U.S. exchanges, in line with the daily average for the past 20 trading days, according to Thomson Reuters data.
NYSE advancing issues outnumbered decliners 4.84-to-1; on Nasdaq, a 2.54-to-1 ratio favored advancers.
The S&P 500 posted 28 new 52-week highs and no new lows; the Nasdaq Composite recorded 165 new highs and 14 new lows. (Additional reporting by Yashaswini Swamynathan in Bengaluru; Editing by Don Sebastian and Nick Zieminski)