Slippage: why larger crypto orders cost more per coin

The best price on an exchange only covers so many coins. A bigger order buys the next, dearer ones too, so its average price is higher.

Worked example

Suppose the asks are 0.01 BTC at A$100,000, 0.02 BTC at A$100,200 and 0.05 BTC at A$100,500. A A$5,000 market order takes all of the first two levels and part of the third, and receives 0.0498607 BTC: an average of A$100,279 per BTC, 0.28% above the best ask (before any fee).

Market orders and limit orders

A market order fills now, at whatever the book offers. A limit order sets the most you'll pay, so it can't slip past your price, but it may fill only partly or not at all. Some exchanges charge less for limit orders that wait on the book, but that depends on the exchange and the order.

Why the cheapest exchange can change with size

An exchange with a good top price but little behind it can be the cheapest for A$100 and the dearest for A$50,000. The trade size lab runs the same comparison at five sizes so you can see where that happens.

Compare exchanges at five trade sizes

Related guides

Further reading: ASIC Moneysmart. Examples use round illustrative prices, not live quotes; the tools use live order books. General information, not financial, investment or tax advice.