Deutsche Bank said the Fed’s decision to hold rates and limited detail from the
Fed chair prompted a sharp steepening of the US Treasury yield curve, lifting
the 30-year yield to 5.20% and pressuring equities. The S&P 500 posted its worst
single-day drop in seven weeks, closing down 1.52% after wide intraday swings —
down more than 0.5% ahead of the FOMC, briefly rallying during the chair’s press
conference, then plunging in the final hour. Tech weakness, including a 5.33%
collapse in the Philadelphia Semiconductor Index, dragged the Nasdaq-100 down
2.06% and into a technical correction, about 11.3% below its early-June peak.
Asian and European markets were mixed.