(For a Reuters live blog on U.S., UK and European stock markets, click LIVE/ or type LIVE/ in a news window) * Weekly jobless claims dip, but still remain high * Q4 GDP grows at consensus-matching 4% rate * GameStop, AMC fall as platforms restrict trading * Indexes up: Dow 1.97%, S&P 1.86%, Nasdaq 1.22% (Adds comments, updates prices throughout) Jan 28 (Reuters) - Wall Street’s main indexes jumped on Thursday as mega-cap technology stocks tried to regain lost ground following a sharp sell-off after fears eased around hedge funds selling off long positions to cover a short squeeze. Shares in GameStop Corp and AMC Entertainment Holdings Inc tumbled as trading platforms including Robinhood and Interactive Brokers restricted trading in stocks that soared this week in a social media-driven trading frenzy that shook stock markets. “If it (GameStop) had kept going higher, that just means more hedge funds would have had margin calls. I think when it backed off a little bit, the market breathed a sigh of relief,” said Thomas Hayes, managing member at Great Hill Capital LLC in New York. All of the 11 major S&P 500 sectors were higher by early afternoon trading. Heavyweights including Microsoft Corp, Facebook Inc , Netflix Inc and Alphabet Inc led gains, after the U.S. stock indexes suffered their worst day in three months on Wednesday. With the quarterly earnings season in full swing, market participants have now started to question whether companies including Apple Inc, Facebook and Tesla Inc could sustain their high valuations. “Investors are digesting earnings that came out overnight and this morning, and taking a look at the fundamentals of what’s going on in specific companies, as well as any outlook that can be provided to try to justify valuations,” said Brian Vendig, managing executive at MJP Wealth Advisors in Westport, Connecticut. Apple reported holiday-quarter sales and profit that beat Wall Street expectations, however, shares of the iPhone maker fell 2%. Facebook rose 0.7% on soundly beating quarterly revenue estimates, while Tesla shed 3.2% after posting disappointing fourth-quarter results and failing to provide a clear target for 2021 vehicle deliveries. A Commerce Department report showed fourth-quarter gross domestic product increased at a 4% annualized rate, in line with expectations, as the virus and lack of another spending package curtailed consumer spending. A separate report showed 847,000 more people likely filed jobless claims last week, lower than expectations of 875,000. Concerns about slowing momentum in economic recovery due to rising coronavirus cases, heightened stock market valuations, and uneven distribution of vaccine rollouts have kept investors on edge about a pullback and increase in volatility in the near-term. At 12:02 p.m. ET the Dow Jones Industrial Average was up 597.54 points, or 1.97%, at 30,900.71, the S&P 500 was up 69.83 points, or 1.86%, at 3,820.60, and the Nasdaq Composite was up 162.39 points, or 1.22%, at 13,432.99. Among other stocks, Comcast Corp added 6.9% after it reported better-than-expected fourth-quarter revenue, as broadband demand continued to offset pandemic-related weakness in its theme park and filmed entertainment businesses. Advancing issues outnumbered decliners for a 2.33-to-1 ratio on the NYSE and a 1.20-to-1 ratio on the Nasdaq. The S&P index recorded nine new 52-week highs and no new low, while the Nasdaq recorded 74 new highs and eight new lows. (Reporting by Devik Jain and Shreyashi Sanyal in Bengaluru; Editing by Shounak Dasgupta)