Will the bank's fixed investment lose money like stocks?
No, even if you buy stocks, you won't lose your money overnight, and you won't owe the bank money! The phenomenon you are talking about is futures, but it is not money owed to banks, it is futures. Banks in China can't invest directly, but only do some agency business. In addition, I want to tell you that fixed investment is a compulsory way to save money, and profit is secondary.