Leading technology stocks have led a jaw-dropping rally over the past five days, propelling a major exchange-traded fund to one of its best weeks in years. The Technology Select Sector SPDR Fund (XLK) surged 8.2% this week, its biggest gain since November 11, 2022, when the fund rose 10.04%. In the same month, the artificial intelligence chatbot ChatGPT was launched to the public for the first time. XLK YTD Mountain Technology Select Sector SPDR Fund (XLK) performance this year. Investors can thank a rebound in big tech and semiconductor stocks this week that boosted all three major U.S. stock indexes. Office and Windows maker Microsoft and artificial intelligence chip maker Nvidia are the top two stocks on XLK, ending the week up about 7.2% and 15.8% respectively. Nvidia shares surged after choppy midweek trading, triggering a market reversal when CEO Jensen Huang touted huge demand for its Blackwell chips at the Goldman Sachs Communacopia+ technology conference. Apple released new versions of iPhone, AirPods and Apple Watch earlier this week, and its stock price rose less than 1%. In the past, the iPhone maker's annual product launches typically caused the company's stock price to fluctuate 3% to 6% within 15 days after the launch. Shares of semiconductor supplier Broadcom, the technology fund's fourth-largest holding, soared 22.4% this week. XLK is up 14.4% this year, trailing the SPDR S&P 500 ETF which is ahead at 18.4%. The fund's shares are also 7.4% below their mid-July record, while the S&P 500 is less than 1% below its all-time high that same month. Despite this week's rebound, it has left investors questioning whether the rally in tech stocks is a “dead cat bounce” following brief declines in early August and September, or a more sustained rally. “This week's recovery in demand for tech and semis is constructive, especially with buyers once again entering near the 200-day moving average,” said Adam Turnquist, chief technical strategist at LPL Financial. “However, we believe this week's rebound was insufficient. “The breadth and relative strength of the sector have clearly deteriorated, while the technology sector or the PHLX Semiconductor Sector Index (SOX) has yet to clear resistance at its August highs,” he continued. Worryingly, only one-third of the sector's Chip Index stocks are trading above their long-term uptrend, compared with 90% in July. Turnquist said this alone shows that semiconductor stocks have lost their leadership position, at least for now.