Your fintech has committed to paying a supplier USD 100,000 in 30 days. Spot rate today is 1500 NGN/USD = ₦150M. If NGN devalues to 1700 NGN/USD by payment date, the same USD 100,000 will cost you ₦170M, a ₦20M loss for waiting. To LOCK today's economics, you buy a 30-day USD/NGN forward at, say, 1520 (the forward rate factors in the interest-rate differential). On day 30, regardless of where spot is, you pay ₦152,000,000 and receive USD 100,000. The forward itself is a derivative that has to be MARKED TO MARKET on your books every period close. This lesson posts the forward at trade date and at one mark-to-market interval.