U.S. stocks extended their pullback on Wednesday, with the S&P 500 sliding below the psychological 6,400 mark and reaching roughly 6,360 intraday—about 2% lower for the week following last Friday’s options-expiration rally. Market participants attributed the move to an unwind of crowded momentum trades rather than a shift in economic fundamentals. Volatility remained contained: VIX futures were only around 20 cents higher, while Bitcoin, which had led the downturn on Monday and Tuesday, staged a rebound during the session. Palantir Technologies was among the hardest-hit individual names. The data-analytics company’s shares fell to $145, closing the gap left by its recent earnings release and trimming the stock’s valuation to about 486 times trailing profit from roughly 600 times earlier this week. The shares later clawed back nearly $10, trading close to $155 by mid-afternoon. Attention now turns to Federal Reserve Chair Jerome Powell’s appearance at the Jackson Hole symposium on Friday. Several desks say a recovery by the S&P 500 above 6,400, potentially catalyzed by Powell’s remarks, is key for any sustained rebound in risk assets.