Much of that advance has been led by momentum stocks, or stocks that investors have been bidding upwards precisely because they already were rising, thereby creating a self-reinforcing trend. Now, Morgan Stanley says these momentum stocks are stalling, which the firm says is an ominous warning sign of both a recession and major stock market declines ahead. “The last two times we’ve experienced a momentum breakdown this severe, it preceded or coincided with an economic recession,” warns the U.S. equity strategy team at Morgan Stanley headed by Mike Wilson.