Alpaca and ProjectX differ on 15 of 21 points TradersPost compares: authentication, stocks, stock options, futures and 11 more. Both support market orders, limit orders, modify open orders and paper accounts.
Authentication
OAuth
API key
Stocks
Supported
Not supported
Stock Options
Supported
Not supported
Futures
Not supported
Supported
Crypto
Supported
Not supported
Short selling
Partial
All but Crypto
Supported
Fractional quantity
Partial
All but Stock Options
Not supported
Stop orders
Limited
Crypto: Stop-limit only. Plain stop orders are not offered.
Supported
Trailing stops
Partial
All but Crypto and Stock Options
Supported
Bracket orders
Partial
All but Crypto and Stock Options
Not supported
Stop limit orders
Supported
Not supported
Day orders
Partial
All but Crypto
Supported
Good till canceled orders
Partial
All but Stock Options
Not supported
Immediate or cancel orders
Partial
All but Stock Options
Not supported
Fill or kill orders
Partial
All but Crypto and Stock Options
Not supported
Alpaca: short selling and day orders aren't available on crypto.
Alpaca: fractional quantity, good till canceled orders and immediate or cancel orders aren't available on stock options.
Alpaca: trailing stops, bracket orders and fill or kill orders aren't available on crypto and stock options.
Link to this comparison /compare/connections/alpaca-vs-projectx
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