Respuesta :
The main way in which bull market investing weakened the stability of the stock market is that it led to speculation, which greatly inflated the price of stocks beyond the companies' value--meaning that the stocks were overpriced in a financial bubble that was bound to "burst".
Bull market investing makes investors thinks they are good at investing. In a bull market, stocks continue to go up well beyond expectations. When the stock market starts to correct down, those newer investors tend to panic and sell to soon. Therefore the stability of the market is weakened when short term investors start to sell.