IRS considers everyone an investor unless they have filed for mark to market accounting as a trader. To be approved as such is not easy and you will want to find a CPA who specializes in Trader Taxes. The rules for Traders are quite demanding, be sure your CPA has many existing clients who elect mark to market. The most important aspects are the number and frequency of trades (it must be substantial and very frequent. I believe the minimum is 1000 trades in a given year but you'll want to check if that's current and there should not be long gaps of time between trades. The latter should not be an issue because if there are 252 trading days that would require a minimum of 4 trades every day). The holding period of each trade (the trader must prove they are trying to profit from daily price movements, therefore your CPA will likely suggest you segregate investments into a different account from your trading account. A long holding period in your trading account will negatively affect you). Again, check with a qualified CPA who specializes in working with TRADERS. See IRS Topic 429 for more background.
Yes, it's best to let a CPA do your taxes for a variety of reasons, and to not hesitate to contact a tax attorney at the first hint of any trouble. I never do my own taxes, even though I could if I wanted to take the time. But a pro will do it better and be less likely to make mistakes. The IRS is an org that I want as little to do with as possible, particularly seeing as how they've gotten so corrupt and incompetent. The last thing I want is for one of those IRS hacks to decide to freeze my accounts and clean them out, then for me to have to spend a fortune fighting to get my life savings back just because they thought something was fishy with my totally legit business, or because I happen to support and contribute a little money to Republican / "tea party" politicians or whatever. One fundamental thing to keep in mind (regardless of whether the IRS will consider your trading / investing as eligible for special tax treatment or as your primary occupation) is the difference in longterm and shortterm capital gains taxes. I have long been able to write certain things off for my asset management business and personal investing activities. Hire a tax advisor.
