Bittex is the most popular cryptocurrency exchange out there. The exchange is now pushing some updates regarding placing orders. They justify the changes for showing their ‘commitment’ to providing fair and efficient price discovery. They feel that these changes will improve overall trading experience on their markets. Effective today, Bittex will remove orders that are older than 28 days. Many orders have no reasonable expectation of being filled and clog the order books. So this is a good idea.