Have you ever noticed that Swap is one of the costs that beginner traders often overlook?

It’s not as obvious as the Spread or Commission, but it gradually eats into your profits every night.

Swap means the fee for holding a position overnight, or in financial terms, "Overnight Interest."
It arises from the difference in interest rates between the two currencies.
When you trade EUR/USD, you are "borrowing" one currency to "buy" the other, and each central bank has its own policy interest rate.

For example, if EUR has an interest rate of 4.0% per year and USD has 5.0% per year, when you Buy EUR/USD, you earn interest on EUR but pay interest on USD.
The difference is -1.0%, meaning you will pay Swap (which is negative).
Conversely, if you Sell EUR/USD, you will receive a positive Swap.

But in reality, brokers act as intermediaries in this borrowing process.
They add their own "handling fee," so even in theory, you should get a positive Swap, but the actual amount may be less than expected or even negative on both sides.

What traders need to know is that Swap Long (for Buy orders) and Swap Short (for Sell orders) are not exactly the same.
Another thing to watch out for is the 3-Day Swap. On Wednesdays, brokers charge triple Swap because the Forex market is closed on Saturday and Sunday, but interest still accrues.
This must be accumulated and calculated on trading days.

Calculating Swap before opening a position is very important.
On standard platforms like MT4 or MT5, go to Market Watch, right-click on the asset, and select Specification.
The figures will be shown in Points or Percentage, depending on the platform.

There are two ways to calculate Swap:
If shown in Points, multiply the Points by the value of 1 Point.
If shown as a percentage, multiply the total position value by the Swap percentage.
For example, if you buy 1 Lot EUR/USD at 1.0900 and the Swap Long is -0.008% per night, and the position value is 109,000 USD, the Swap fee would be approximately 8.72 USD per night.

An important point to understand is that Swap is calculated based on the full position value, not the Margin you put up.
If you leverage 1:100 and only put up 1,090 USD in Margin, but you pay 8.72 USD in Swap per night, that’s 0.8% of your Margin per night.
This hidden cost can be quite frightening.

Swap is not just about risk; it also creates opportunities for some traders.
Carry Trade strategy involves "borrowing" a currency with low interest and "buying" a high-interest currency to earn positive Swap daily.
For example, buying AUD/JPY because AUD has high interest and JPY low.
But the risk is that if the exchange rate drops sharply, the loss could outweigh the accumulated Swap profits over the years.

Another option is Swap-Free or Islamic accounts, which do not charge Swap regardless of how long the position is held.
They are suitable for Swing Traders or Position Traders who want to hold positions for weeks or months.
However, brokers often compensate by widening the Spread or charging a fixed fee.

In summary, Swap impacts different trading styles differently.
Short-term traders are hardly affected, but those holding positions for months or years should consider Swap seriously.
Choosing a broker that is transparent about fees and clearly displays Swap information will help you plan your trades carefully, avoiding hidden costs that could surprise you later.