The red-hot US stock markets continue to power inexorably higher, fueling extraordinary complacency and euphoria. With stocks riding an extreme deluge of Fed money printing, selloffs are minor and far between. But are these seemingly-perpetual gains to endless lofty record highs justified fundamentally? The big US stocks’ winding-down Q1’21 earnings season illuminates how these elite companies are faring. The performance of the flagship US S&P 500 stock index (SPX) has been amazing. In the first quarter of 2021, this dominant stock-market benchmark surged 5.8%. During those 61 trading days, the SPX hit new all-time-record closes on fully 15. The SPX stretched as high as 17.0% above its baseline 200-day moving average, extremely-overbought territory. Yet traders think the Fed has rendered material selloffs extinct.