The S&P 500 and Nasdaq opened solidly lower as the 10-year Treasury yield raced above 4% on jobless claims and eurozone inflation data. But the major indexes rebounded from and above key levels. The Dow Jones led, fueled by Salesforce surging on earnings. Aehr Test Systems had a wild day on Tesla-related fears. Dexcom, which had its own existential threat last week, jumped near a buy area on positive Medicare news.