NEW YORK, Aug 27 (Reuters) - Wall Street rallied on Friday, with the S&P and the Nasdaq notching record closing highs for the fourth time this week as U.S. Federal Reserve Chairman Jerome Powell"s remarks at the Jackson Hole Symposium calmed fears over the tapering timetable and sent investors into the weekend in a buying mood. All three indexes posted weekly gains. "I see two things happening," said Mike Zigmont, head of research and trading at Harvest Volatility Management in New York. "I see a reflexive dip-buying validation and I see the market embracing a dovish Fed." Regarding the indexes" recent string of all-time highs,including the S&P 500"s 52nd record high close so far this year, Zigmont said "The march north has been very consistent. The drawdowns are super shallow, and the recoveries are very fast." In his prepared remarks, Powell stopped short of providing a clearer picture regarding the timing of the central bank"s tapering of asset purchases or hiking interest rates, the key elements of its dovish monetary policy aimed at helping the economy recover from the pandemic recession. read more Indeed, Powell appeared to strike a more dovish tone than other Federal Open Market Committee (FOMC) officials, including St. Louis Fed President James Bullard and Cleveland Fed President Loretta Mester, who said earlier in the day that they expect the tapering process to begin soon and wind down next year. "The market is very happy that the Fed is pumping more liquidity into the economy every month," Zigmont added. "The Fed is enabling asset prices to climb and the market is pleased with that." Economic data released on Friday delivered, in large part, precisely what economists expected - a pullback in consumer spending and sentiment due to the COVID-19 Delta variant, and signs that the current wave of price spikes will not morph into long term inflation, inline with Fed assurances. read more Unofficially, the Dow Jones Industrial Average (.DJI) rose 241.63 points, or 0.69%, to 35,454.75, the S&P 500 (.SPX) gained 39.33 points, or 0.88%, to 4,509.33 and the Nasdaq Composite (.IXIC) added 180.08 points, or 1.2%, to 15,125.89. Among the 11 major sectors of the S&P 500, energy shares (.SPNY) enjoyed the largest percentage gain. Apparel retailer Gap Inc (GPS.N) advanced following its full-year net sales forecast hike. read more Chipmaker Nvidia"s (NVDA.O) shares rose after sources said it would likely seek antitrust approval from the European Union to take over British chip designer Arm. read more Workday Inc (WDAY.O) jumped as brokerages upped their price targets for the stock after the company beat second-quarter revenue estimates. Stay-at-home darling Peloton Interactive Inc (PTON.O) slid following its profit warning and its announcement it was being probed by U.S. regulators over an accident involving the safety of its treadmills. read more Beijing continued its crackdown on its tech companies, threatening to curb their ability to list on U.S. exchanges. U.S.-listed shares of Alibaba Group and Tencent Music Entertainment (TME.N) dropped, as did the Invesco Golden Dragon ETF. read more