What makes bitcoin different
Bitcoin has one network, and it is slow and expensive. A transfer between exchanges takes from ten minutes to an hour, and the withdrawal fee on most venues sits at a few dollars regardless of the amount.
From that follows the thing that governs all work with BTC: the classic "buy here, transfer, sell there" barely works on bitcoin. While the coin is in flight the spread closes — it lives for seconds and the transfer takes tens of minutes.
How it is actually done
By holding balances on both exchanges in advance. Then the route executes instantly: sell where it is dearer, buy where it is cheaper, and end with the same total holdings. The transfer happens afterwards, calmly, once the spread is already captured.
That changes the capital requirement: not one deposit but one per venue. In exchange, the main risk disappears.
What to watch in the table
The spread is computed from best prices net of the trading fee. The withdrawal fee is not included, and on bitcoin it weighs heavily: a three-dollar fee on a hundred-dollar transfer is three percent, more than any spread.
So the rule is simple: the smaller the amount, the less sense moving BTC makes. On small sizes bitcoin is a coin to trade within one exchange, not between them.
Where spreads are usually wider
Between large venues bitcoin spreads are tight: it is the most liquid coin on the market and automated systems close gaps within fractions of a second. Visible differences appear either on small exchanges with thin books, or during sharp price moves when venues fall out of sync.
The second is a real opportunity; the first is usually a trap, because on a thin book the visible price holds for a couple of hundred dollars.
