FCMs and IBs must file form SAR to report suspicious transactions that are conducted or attempted by, at, or through the firm and involve an aggregate of at least $5,000 in funds or other assets (not limited to currency). A transaction is suspicious if the Member knows, suspects, or has reason to suspect that the transaction or pattern of transactions: 1) involves funds that come from illegal activity or are part of a transaction designed to conceal that the funds are from illegal activity; 2) is designed, such as through structuring, to evade the reporting requirements of the Bank Secrecy Act; 3) does not appear to serve any business or apparent lawful purpose; or 4) involves the use of the FCM or IB to facilitate a criminal transaction. In most instances, the SAR is due within 30 days after the firm becomes aware of the suspicious transaction.