Interactive Brokers and Tradier are the only two currently supported per the Linked Account help.
I use it for Interactive Brokers and it works very seamlessly, especially for margin accounts. For non-margin accounts, rebalances are a little trickier if you don’t carry a sufficient cash balance. Usually one or more buy orders are rejected when I send a wave rebalance orders in a non-margin account due to insufficient funds, so I manually reschedule them (via the p123 trade page) till later in the day. It would be handy if p123 had a way to schedule orders based on cash balances rather than by time, e.g. submit this buy orders for 1000 shares @ 25.00 when the cash balance is >= 25k USD, so that it didn’t require as much manual tending.
That said, the biggest limitations for me are:
- Only US markets are currently supported
- Only a handful of IBKR algos are supported (VWAP, POV, and pegged)
- No integration with IBKR short sale borrow rates and shares available
The latter is really more of a data issue and not a trading issue, but the combination of the three may cause me to explore alternative methods for order submission.