Buying a stock, or taking a ‘long position’ in financial jargon, is what you do when you expect the price of that stock to go up. If, on the other hand, you expect the price of a stock to go down, you can take a ‘short position’. This can be done by borrowing stocks from a third party and then selling these. When the price indeed goes down, you can buy the stocks back at a lower price before returning them to the lender, and thus make a profit. Nowadays, this is an everyday activity for many stock traders, made easy by the services of brokerage firms. Remarkably, it was also daily practice in…