When you think that BTC will fall hard, you choose a short position. You borrow BTC from the exchange and it will be sold directly for you and converted into dollars. The position has only just opened so there must come a time when you can buy back that Cryptocurrency with the dollars for which they were purchased. If the exchange rate has fallen, you keep dollars from this transaction and you, therefore, make a profit. If the price has risen, you will have to add dollars to buy the Cryptocurrency and close your position. Again, the debt will be taken from your collateral margin to make up for the difference. The perfect usage of the Aktueller IOTA Kurs happens to be essential here.
With margin trading, you can choose which rate to use for trading. For example, you can choose to use Cryptocurrency against the dollars or Cryptocurrency against