LESSON 7 · NOTES

Fees: where the spread disappears

A 2% spread turned into 0.3% in the account. We go through the six places where the other 1.7% went, and what to do about each one. The strategy is spot-spot across two centralized exchanges.

Three takeaways

1. Fees are only part of the cost. The exchange and the network charge you openly. The order book, slippage and time take their share quietly, and usually take more.

2. The gross spread is not what you get. 2% on screen and 0.3% in the account is not a mistake. It is the cost of a trade nobody priced.

3. Do the math before you enter, not after. Net spread: on ask and bid, with fees, with order book depth, with transfer time.

One trade, step by step

The strategy here is spot-spot between two centralized exchanges, the simplest one. There are others: spot-perp, spot-margin, perp-margin, perp-perp; and once a DEX joins the pair, it brings its own costs, such as gas and bridge transfers. Every strategy has its own quirks, but the principle is roughly the same: count what will be left. The worked example: a 1,000 USDT trade with a 2% spread, so we expect 20 USDT. The proportions are realistic for a thin coin; the amounts are illustrative.

1. Exchange fee

Charged on every trade. The base spot rate on large exchanges is around 0.1% (taker); on futures it is hundredths of a percent. VIP tiers and paying with the exchange’s own token bring it down. A tenth of a percent sounds like nothing, and on its own it is. But we pay it twice, on the buy and on the sell: 0.2%. And the target is a 2% spread. 0.2% out of 2% is a tenth of what we want to earn. In two-leg strategies (spot-perp, perp-perp) there are four trades, two to open and two to close, and futures have their own fee. What to do: when you don’t need instant execution, place a limit order and be the maker. The fee is lower.

2. Withdrawal fee

Not a percentage of the transfer, but a fixed price per transfer, the same for any amount. 1 USDT on a 1,000 transfer is 0.1%; the same 1 USDT on a 100 transfer is already 1%, half the spread. On small amounts people usually either lose money or earn nothing if they didn’t count the fee in advance. What to do: count every cost before you transfer.

3. The order book: ask and bid

The chart price is the last trade. You buy at the ask (slightly higher) and sell at the bid (slightly lower). The spread “by last price” is 2%; the spread by ask and bid is already 1.8%.

The real spread is not the difference between last prices. It is the ask where you buy minus the bid where you sell.

4. Slippage

Your order eats through several levels of the book, each one pricier than the last. On a liquid coin, 1,000 USDT won’t even register; on a thin one (and 2% spreads tend to live exactly there) it is 0.2% or more on each side. What to do: check order book depth before you enter.

5. Time

Most transfers take a couple of minutes, but sometimes one gets stuck for half an hour. While the coin is in transit, the spread lives its own life: you saw 2%, and five or ten minutes later it may be gone, may be negative, or may even have grown. Other arbitrageurs may well have got there first. In our example the spread narrowed, and that cost 8 dollars out of 20. This is the only cost with no exact amount. A fee has a price; time doesn’t. Time is not a cost, it is a risk. In schemes inside a single exchange (spot-perp, perp-perp) this line doesn’t exist, since there is nothing to transfer. Instead, they have a cost of their own: funding. What to do: keep capital on both exchanges in advance. Then there is nothing to transfer, and the time risk is gone. From the first lesson, “the money has to sit in both places”: this is why. How to do that in practice is covered in the following lessons.

1. Calculate the net spread before entering. On ask and bid, with fees, with depth, with time. If little is left, don’t enter.

2. Be the maker where you can; don’t move small amounts around.

3. Keep capital on both exchanges in advance. The least predictable part of the trade, time, disappears: there is nothing left to transfer.

Terms

• Gross spread: the price difference you see on screen or in a scanner, before any costs.

• Net spread: what is left after fees, the order book, slippage and time. It is the only thing you actually get, which is why you calculate it in advance.

• Explicit costs: exchange and network fees. They show up in your statement.

• Hidden costs: the order book, slippage, time. They don’t appear in your statement, but they are bigger than the explicit ones.

• Maker / taker: whoever places an order and waits pays less; whoever fills someone else’s order pays more.

• Slippage: the difference between the expected price and the average price you were actually filled at.

Check yourself

The spread by last price is 2%. Why is that not the spread you will get?
Because you buy at the ask and sell at the bid. The real spread is the ask where you buy minus the bid where you sell. It is always smaller.

Why is the withdrawal fee more dangerous for small amounts?
It is fixed. The same dollar is 0.1% of a thousand and 1% of a hundred.

Which cost disappears if you keep capital on both exchanges?
Time. There is nothing to transfer, so the spread has no chance to narrow while you wait.

Fees were checked on September 11, 2026 against the base tiers of large exchanges; they change, so check the fee page of your exchange.

Next lesson: how to choose an exchange and not lose money at the start — which signs to look at, and which to ignore. After that comes the practical track: each strategy broken down on real examples with the same kind of calculation. The Telegram channel @arbiq_ai posts more often than the lessons come out: trade breakdowns, what is happening in the market, answers to questions · t.me/arbiq_ai

This material is for educational purposes only and is not investment advice. Any trading decisions are yours alone and at your own risk.