I've been running a small stock portfolio thru TD waterhouse but my last trade ended up giving me a negative cash balance (-16.00) due to brokerage fees. To settle it I figure I'll just overcontribute and eat the 1% of overcontribution/month penalty till the end of the year (16*.01*9) = $1.44. TD advised me not to do it, but I assume they're just doing their due dilligence in telling me not to. Can anyone here think of a good reason not to do this?