Alpaca and Public.com differ on 11 of 21 points TradersPost compares: index options, fractional quantity, stop orders, trailing stops and 7 more. Both support stocks, stock options, crypto, market orders, limit orders and stop limit orders.
Index Options
Not supported
Supported
Fractional quantity
Partial
All but Stock Options
Partial
All but Stock Options and Index Options
Stop orders
Limited
Crypto: Stop-limit only. Plain stop orders are not offered.
Supported
Trailing stops
Partial
All but Crypto and Stock Options
Not supported
Bracket orders
Partial
All but Crypto and Stock Options
Not supported
Day orders
Partial
All but Crypto
Supported
Good till canceled orders
Partial
All but Stock Options
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
Modify open orders
Supported
Not supported
Paper accounts
Supported
Not supported
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.
Alpaca: day orders isn't available on crypto.
Public.com: fractional quantity isn't available on stock options and index options.
Link to this comparison /compare/connections/alpaca-vs-publiccom
Brokers change their rules, so check their docs before you connect. TradersPost does not recommend a broker.