There are a number of reasons why your stock order could’ve been canceled or rejected:
Your order was routed to one of our executing brokers that can’t accept orders for a particular stock: In this case, simply reenter the order, and one of our stock brokers will make sure it gets routed appropriately. If you continue to experience issues, please send us a note.
Your limit order is too aggressive: your limit order may also be rejected if it fails one of our risk checks. Risk checks help us to identify orders that don't quite make sense in the context of where the stock is currently trading in the market, such as a $1,000 limit sell order for a stock currently trading at $5. This means that your order may be canceled if the price of the security moves significantly away from your limit or stop price and is then seen as too aggressive.
You incorrectly placed a stop order: A stop order converts to a market order or a limit order once the stock reaches your stop price. However, if you set a stop order for a stock at its current price, we’ll reject your order. Additionally if you set a stop order which would execute immediately (e.g. a buy stop order below the current market price, or a sell stop order above the current market price), we’ll reject your order.
The stock executed a split: If a stock undergoes a reverse split, we’re required to cancel all open orders.
Margin call risk: Your Good-til-Canceled (GTC) BUY Order(s) could be cancelled if your account doesn't have enough buying power to support them. Buying power is the amount of money you can use to purchase stocks, options, or cryptocurrencies.You may find yourself with negative buying power if your portfolio value drops below your initial margin requirement. While having negative buying power doesn't necessarily mean that you're in a margin call, we cancel these orders because they would put you at a much higher risk of a margin call.