A day trading pattern (PDT) occurs when an investor carries out 4 (four) or more day trades in a period of 5 working days, as defined by FINRA (Financial Industry Regulation Authority), the American regulatory body, similar to ANBIMA in Brazil. Traders who exhibit this pattern of day trading are subject to PDT restrictions and may have their accounts blocked for a period of 90 days, during which time no new positions can be purchased.
To learn more about those restrictions, access here.