If there were not some mechanism for changing the price of a stock, the price of the stock could become like the national debt where it goes up exponentially every day of the year. We could far surpass the value of the company or the whole GNP. I see nothing illogical about the ability to short a stock to keep it where people estimate to be the value of the stock. Naked shorting and other means are whole other story. I have never shorted an individual stock myself, but, see nothing wrong with the theory. I have bought short ETFs which is a little different.