Short selling is a way to make money when a security price starts falling. When you expect a stock to fall in price, you borrow it from your broker and sell it. After sometimes buy it back in order to return it to your broker. The difference between the selling price and the buying price in this case is your capital gain.
Short selling works if the price continues to fall. If the price does not fall or retraces after sometime, you can make a hefty loss on your short position. The loans that are taken in order to go short have to be repaid! If the lender asks them or the price goes up, the trader has to buy back shares in order to make the repayment. Now, the harder it becomes to get the right number of shares in the market, the more desperate the trader will become and the higher the prices can go.
In case of futures or options, you don’t need to borrow the security; you simply agree to sell the contract when you go short. Why do investors take a short position? The most obvious reason is that they are expecting the price to go down further. Short selling is also used for hedging purposes.
In the case of stocks, you need to monitor the rate of short selling in order to gauge investor expectation as well as the future market direction. Now, NYSE and NASDAQ report the short interest in stocks listed with them. Now this data is released on monthly basis as the brokerage firms may need a while to report how many shares have been shorted and then report that data to the exchange.
Short Interest Ratio is very important for short sellers. Short Interest Ratio can give you important clues about other short sellers in the market. Too much short selling can only drive the stock price down.
So what is the Short Interest Ratio? Short Interest Ratio is the number of shares of a particular stock that has been shorted in the market. It also reports the percentage change in the short positions from the previous month. Plus the average daily volume for that stock in the same month and also the number of days of trading at the average volume that it would require the market to cover the short positions in that stock.
The problem with Short Interest Ratio is that it is not calculated frequently. It is calculated on monthly basis. So, the trader cannot use it to gauge the short positions in the market on a daily or weekly basis. However, it can give you the general trend in the market. A high short interest ratio should make you nervous if you have taken a short position in that stock as most of the investors who are short will soon become desperate to dump that stock in the market and cover their short positions.