US stocks end mixed session marked by a sell-off in Big Tech stocks Investors got spooked by a mix of concerns about rising inflation, fears the Fed may have to pull back monetary stimulus earlier than thought, and the potential for tax increases 4:05pm: US equities close mixed session US stocks end a mixed session marked by a sell-off in Big Tech stocks. Investors got spooked by a mix of concerns about rising inflation, fears the Federal Reserve may have to taper monetary stimulus earlier than thought, and the potential for tax increases. Also, Treasury Secretary Yellen’s comments about interest rates didn’t help the market. She said rates may have to rise somewhat to keep the economy from overheating.