The heavy work on the cleaning of the Market section has been completed. As of today, any and all threads made to Buy, Trade or Sell will have an expiration period of 6 months. This period does not take into account wether your item has been sold, found or traded, so if you want your topic to remain make sure to bump it every now and then.
For WTS topics, this means it will be locked and moved to History. For WTB/WTT topics , this means it will be deleted.