Do I have to pay a trading fee for both buying and selling? How many times is a complete round trip charged?
Answer: Usually 2 times.

Many beginners think that if a fee is charged when you buy, it won’t be charged when you sell.
Actually, buying and selling are two independent executed trades:
One buy → incurs one fee
One sell → incurs another fee

Here’s a simple example: Suppose you trade with 1000U and the fee rate is 0.1%
Example:
Buying fee: 1000 × 0.1% = 1U
Selling fee: about 1U
For a complete round (buy once and then sell once), the total fee is about 2U.
So when calculating trading costs, you can’t just look at the “entry” trade.

Remember this formula: Round-trip trading cost ≈ buying fee + selling fee.
In addition, different account tiers, Maker/Taker, fee discounts, and other factors will affect the actual fee rate. Always rely on the real-time fee shown in your account.
A single fee may not be much, but when your trading frequency is high, the accumulated amount can be noticeably higher than you might expect.
Before trading, don’t just calculate how much you can profit—also figure out exactly what total cost you’ll pay for a full entry and exit.
(For educational purposes about trading mechanics only; not investment advice.)