re: #97 ericblair
There are options that can do something similar: instead of borrowing a stock, you buy put options that allow you to sell a stock for a certain strike price in the future. The put option is a contract that allows you, but does not force you, to sell a set of 100 shares of the stock to the issuer at a given date in the future.
We need to recognize that these “financial products” are basically a legalized form of gambling and regulate them like casino games rather than as financial market transactions.