The basis for the order reasonability rejections may vary but are all related to the order price relative to the current market.  These reject messages are implemented as precautionary and are intended to prevent orders from being executed based on erroneous price submissions.  Some scenarios that may cause these types of rejections are as follows;

• If a security has no active quote (no bid or ask price) traders may be prevented from submitting market orders.  This is a protective restriction that attempts to prevent executions from occurring at prices significantly different than the value of the security.  Traders are able to transmit and execute limit orders for a security that is not displaying a market quote.
• Traders attempting to enter orders at prices through the market and significantly inferior to the current mark price may receive a rejection indicating that the price is not reasonable.  Examples would be an order to buy at a price well above the mark price or a sell order at a price that is well below.  Modifying the price to a level closer to the mark price should allow traders to successfully execute the order. 
• If our systems are unable to make a determination as to the reasonableness of an order, a warning will be displayed indicating that the reasonableness cannot be determined.  Traders receiving this message will have an option to acknowledge the message and transmit the order but should use caution in doing so to ensure that the order being transmitted is what is intended.