QE 1 & QE 2 from 2009 never stopped. They created this bubble. Obama and then trump paying their millionaire and billionaire friends. They suck.You have to ask why? Companies that routinely refinanced debt instead of paying it down. The tax structure is one where debt refinancing was rewarded with deductions, so their cash was better served to pay dividends or stock buy backs. This practice also inflates the price earnings multiples. When Uber went public they had a boat load of cash but no profits. People invested like crazy with hopes this would be their generation's Apple or Amazon. The Fed tried and flinched in 2018 to raise rates and force companies to be more responsible with their debt, but instead lowered rates to protect the market. Powell went into this cycle of rate increases with the tough message that they were not going to worry about the market and investors were going to feel the pain along with the companies that were poorly leveraged. Too much cheap money for too long has led us to this point.