Market orders and limit orders
A market order says: now, at any price
It fills immediately at the best price on offer. Fast and certain to happen, but in a thin or fast market the best price on offer can be noticeably worse than the one you saw.
A limit order says: this price or better
You name the price, and it only fills if the market comes to you. You control the price but not whether it happens. The market can turn just before it reaches your number.
Slippage is the gap
The difference between the price you expected and the price you got is slippage. On big coins it's usually tiny. On small coins, or in a crash, it can cost more than the fee.
A stop-loss is a market order in waiting
On most exchanges, when the stop price is hit a market order goes out. In a sudden drop it fills at the next price available, which can be below your stop. A stop limits a loss; it doesn't fix it to the cent.
Check yourself
You place a limit order to buy at $60,000. Bitcoin dips to $60,050, then rallies to $70,000. What happened?
- You bought at $60,000
- You bought at $60,050
- Nothing: your order never filled
Show the answer
Nothing: your order never filled — A limit order fills only at your price or better. The market never reached $60,000, so you kept your price and missed the move.