Trading, or in other words buying low and selling high! The object that changes owner can be anything. From a share, a dividend or a property to the price of gold, oil or the exchange rate of currencies. WHAT is traded is indeed of no importance, while the PRICE is all that matters. The price after all is the thing that will tell in the end if the trade was a successful one.

Besides, trading has been known to mankind since ancient times. For example, if person A buys 1kg potatoes from person B at 1$/kg and one week later the price of potato has climbed to 1.2$/kg, by selling the potatoes to person C, A has earned 20%. That is, it doesn't matter what anyone trades, as long as he has the knowledge and correct predictions of how the price of the product will move.

Meanwhile, profit can be made through the opposite move, something that is difficult to understand for most of the people. And that is first the product to be sold and then to be bought. In that case, we have made a profit while the prices drop. But how can something be sold when we don't own it?

Let's say person B owns 10lt oil in tanks, which he doesn't need. "A" predicts that the price of oil will drop in the next week. He visits "B" and he borrows that oil paying some commission per day. Then, he sells that 10lt oil at 1$/lt having in mind to buy it back cheaper one week later so that he returns it to "B". Indeed, the price of oil drops to 0.9$/lt. He buys back 10lt oil, which means making a profit of 10% (buy 0.9$, sell 1$), and he returns that to "B", paying him the commission "B" charged for the use of his oil during all that days.

It is obvious now that profit can be made even when prices drop .