Order types by broker
A strategy can only use the orders its broker accepts. This page lists them for the US brokers, Alpaca and Interactive Brokers (IBKR). An order the broker does not accept is refused when it is placed, not silently turned into a different order.
Each list below is what has been verified on Stretus. An order type or feature that is not listed for a broker is not documented for it yet; do not rely on it.
Alpaca
| Order type | Notes |
|---|---|
| Market | Fills right away at the best price available |
| Limit | Fills only at your price or better. Prices below $0.01 (sub-penny) are refused |
| Trailing stop | An exit that follows the price as it moves in your favour, by a price amount or a percentage |
| Feature | Notes |
|---|---|
| Fractional shares | Size the order by value instead of by quantity. You cannot set both |
| Short selling | 110 of the 115 US stocks are shortable |
| Extended hours | Limit orders only, with DAY or GTC, 04:00-20:00 ET |
| Modify an order | Cancels the order and places a new one; the order ID changes |
Interactive Brokers
| Order type | Notes |
|---|---|
| Market | Fills right away at the best price available |
| Limit | Fills only at your price or better. IBKR may cancel a limit priced far from the market |
| Stop | Becomes a market order once the price reaches your stop price |
| Stop-limit | Becomes a limit order once the price reaches your stop price, so it never fills worse than your limit |
| Trailing stop | An exit that follows the price as it moves in your favour |
| Time in force | Notes |
|---|---|
| DAY | Cancelled at the end of the trading day if it has not filled |
| GTC (good till cancelled) | Stays open across days until it fills or you cancel it |
| OPG (at the open) | Fills only in the opening auction |
| IOC / FOK | Immediate or cancel / fill or kill: fills at once (all of it, for FOK) or is cancelled. Not accepted together with a stop order |
| Feature | Notes |
|---|---|
| Short selling | Supported: sell first and buy back later |
| Extended hours | Supported: orders outside the regular 09:30-16:00 ET session |
Stop loss and take profit
On IBKR, a strategy's stop loss and take profit are managed by Stretus, not placed at the broker as a linked one-cancels-other order. Stretus watches the position and sends the exit order when a level is reached.
On Alpaca Paper, a limit order placed outside market hours can fill immediately, while a market order waits for the next open. A live account follows the exchange.
US regulatory fees
US buys carry no regulatory fee. Sells carry the SEC Section 31 fee and the FINRA Trading Activity Fee. See Fees and charges ->.