When trading cryptocurrency on Alpaca, you might notice that the final filled value of your order is slightly different from the "notional value" you initially requested. This occurs because Alpaca implements an automatic 2% price collar on all crypto market orders, converting them into limit orders for your protection.
This mechanism is designed to:
Safeguard against Volatility: In fast-moving crypto markets, prices can change rapidly. The price collar acts as a buffer, preventing your order from executing at an unexpectedly unfavorable price.
Manage Spending: It ensures that your trade doesn't consume more of your funds than intended due to sudden market shifts.
The limit price for your order is set based on the last available ask price (for buys) or bid price (for sells) at the time of order submission, plus or minus the 2% collar.
What this means for your order: For notional market orders (where you specify a dollar amount rather than a crypto quantity), this protective measure may result in a partial fill or a total filled amount that is less than your original requested notional value if the market moves beyond the collar. This is intended to protect you from significant slippage.
For more details on how different orders behave, please refer to our FAQ on What type of orders are supported for cryptocurrency.