I recently withdrew some money from one of my brokerage accounts which caused it to fall below the 25k minimum for classification as day trading account. I know that in a NPDT account, I can only conduct 3 day trades in a rolling 5 day period. However i noticed that after reclassification my buying power remained the same,i.e. 4X buying power, not 2x. I subsequently used this 4X BP unknowingly to conduct a day trade yesterday. I am somewhat confused about the rules. Am I prohibited from doing this, will i suffer some kind of margin call? Can anyone clarify? Thanks.