A bank card is judged to be "fast in and fast out" usually means that the bank card frequently conducts large or abnormal transactions in a short period of time, causing risk warnings from the banking system. Specifically, the circumstances in which a bank card may be judged as "fast in and fast out" include but are not limited to the following aspects:

1. Frequent cross-border consumption: the bank card is frequently used in a short period of time. Cross-border consumption in different countries or regions violates normal consumption behavior patterns.

2. Large-amount transactions: The bank card has carried out several large-amount transactions in a short period of time, exceeding the normal consumption level of the cardholder.

3. Abnormal transaction pattern: The bank card has abnormal transaction behavior that is inconsistent with the cardholder’s regular transaction habits, such as continuous shopping in different cities, or frequent specific types of transactions, such as purchasing virtual goods. Currency etc.

When the banking system discovers these abnormalities, in order to ensure the security of the cardholder's account and reduce risks, the bank may temporarily freeze the bank card and require the cardholder to perform identity verification or contact the bank for further verification. Cardholders can unfreeze their cards and learn about specific processing measures by calling the bank's customer service hotline or going to a bank branch.