A huge multi-month steep decline breaks investors’ euphoria and bullish psychology. For prices to rise and stay up people must be optimistic enough about the future to buy and hold stocks. It takes years of a rising market to bring most people back in. It took 2 years after the 2008 decline (see weekly chart) for the market to recoup its losses and even then people doubted the recovery for years. It took 26 years after the 1929-33 decline. Note the retest of the bottom in 2009 before QQQ finally moved up. The boomers, who hold most of the wealth, will stay away from the market for years as they remain haunted by the debacle of 2020.