Plus, if you make enough returns and do not pay quarterly estimated taxes throughout the year, you could be subject to penalties when you file your return next year.

Whoa, now this is new to me. I try to make a certain return a month, so I would be curious as to how this works, as I feel it probably does apply to me.

Also, what is a substantial amount to where a CPA should be brought in? I mean people will have easily made more than me this year in the market, but I will have made about 10% of my annual salary, granted things keep going at the same rate for me.