It isn't a matter of just deciding that you are a day trader. There are steps.
Special rules apply if you're a trader in securities, in the business of buying and selling securities for your own account. The law considers this to be a business, even though a trader doesn't maintain an inventory and doesn't have customers. To be engaged in business as a trader in securities, you must meet all of the following conditions:
- You must seek to profit from daily market movements in the prices of securities and not from dividends, interest, or capital appreciation;
- Your activity must be substantial; and
- You must carry on the activity with continuity and regularity.
The following facts and circumstances should be considered in determining if your activity is a securities trading business:
- Typical holding periods for securities bought and sold;
- The frequency and dollar amount of your trades during the year;
- The extent to which you pursue the activity to produce income for a livelihood; and
- The amount of time you devote to the activity.
If the nature of your trading activities doesn't qualify as a business, you're considered an investor and not a trader. It doesn't matter whether you call yourself a trader or a day trader, you're an investor. A taxpayer may be a trader in some securities and may hold other securities for investment. The special rules for traders don't apply to those securities held for investment. A trader must keep detailed records to distinguish the securities held for investment from the securities in the trading business. The securities held for investment must be identified as such in the trader's records on the day he or she acquires them (for example, by holding them in a separate brokerage account).
The Mark-to-Market Election
A trader must make the mark-to-market election by the original due date (not including extensions) of the tax return for the year prior to the year for which the election becomes effective. You can make the election by attaching a statement either to your income tax return if filed without an extension or to a request for an extension of time to file your return. The statement should include the following information:
- That you're making an election under section 475(f);
- The first tax year for which the election is effective; and
- The trade or business for which you're making the election.
https://www.irs.gov/pub/irs-pdf/i3115.pdf
