I recently met a trader who claimed he was drawing from his margin trading account to pay his car loan. He said the purpose was to reduce his total interest expense since margin interest is deductible. I told him that I thought it was illegal since you are only 'supposed' to deduct interest for investment related items (thats the rule here in Canada I thought). He claimed it was totally legal and encouraged me to try. This makes no sense to me. Is this possible and if so legal? Also how would you get margin called?