Momentum, the strategy of betting on recent winners, has gone from its biggest four-day plunge since the vaccine-fueled rotation of 2020 to its biggest one-day gain also since 2020. Then a supposedly uneventful Fed meeting raised fresh doubts about new Chair Kevin Warsh's commitment to curbing inflation, pushing long-term Treasury yields higher. Government bond yields finished the week higher, while the S&P 500 eked out a 1% gain. "Higher bond yields further amplify concerns about AI investment by raising discount rates and the cost of capital," Luo wrote in an email. That creates a particularly awkward combination for the AI trade.