Judging from the relevant information, the mortgage of real estate and land of listed companies shows that the company has reached the end of its tether and may declare bankruptcy at any time. If you can't get the land at maturity, you will return it to the bank, and the bank will have no money to recover the loan.
Bad news refers to the bad news that causes the stock to fall. Once there is bad news in the stock market, it will often usher in a short market, and a large number of investors will start selling chips.