Why it is charged twice
A buy is one fill and selling the same notional is another; each is charged on its notional.
So one complete round trip costs twice the single-side amount. In price terms, it is equivalent to needing a gain of about "rate × 2" to cover it.
Formulas
trade size × ratetrade size × rate × 2round-trip cost ÷ trade size = rate × 2Round-trip cost by trade size (0.1% rate)
| Trade size | Single-side fee | Buy-and-sell round trip |
|---|---|---|
| 1,000 USDT | 1.00 USDT | 2.00 USDT |
| 2,000 USDT | 2.00 USDT | 4.00 USDT |
| 5,000 USDT | 5.00 USDT | 10.00 USDT |
| 10,000 USDT | 10.00 USDT | 20.00 USDT |
At a 0.05% rate, halve the amounts above; the round-trip cost is proportional to both trade size and rate.
Notes
At a 0.1% rate the round trip is about 0.2% of the trade size — the price must rise at least 0.2% just to cover the fees.
Slippage, withdrawal fees and funding rates are excluded; the real cost is higher.
FAQ
What does a 2,000 USDT round trip cost at 0.1%?
Single side = 2,000 × 0.1% = 2.00 USDT; round trip = 2.00 × 2 = 4.00 USDT.
Does the round-trip cost relate to the break-even price?
Yes. A 4.00 USDT round trip is 0.2% of the trade size, consistent with the break-even formula conclusion that the price must rise about 0.2%.