Hi, I have trading account with Robinhood and I have lot of short term options opened/closed last year . How do I calculate gain/loss and how I calculate cost basis?

[JohnB5677]

Robinhood should have provided you with a Form 1099-B that outlines all of your "closed" trades.

To post your sales:

Income & Expenses

1. Scroll to Stocks, Mutual Funds, Bonds, Other
2. Answer Yes to Did you sell stocks, mutual funds, bonds, or other investments in 2020?
3. On the OK, what type of investments did you sell? screen, select Stock, Bonds, Mutual Funds. Then select Continue.
4. From here, you can import or manually enter your 1099-B.
5. Answer the questions about your sales. Choose to Enter sales one by one when asked.
6. On the Now, we'll enter one sale on your 1099-B screen, enter your info.
7. Check I have other boxes on my 1099-B to enter and enter the disallowed wash sale loss in box 1g.
8. Select Continue and answer any follow-up questions.

Note: You'll need TurboTax Premier, TurboTax Live Premier, or TurboTax Self-Employed, TurboTax Live Self-Employed, to add any 1099-B forms.

If you've been trading in and out of options, you will probably have Wash Sales.

• A wash sale occurs when an investor sells or trades a security at a loss, and within 30 days before or after, buys another one that is substantially similar.
• It also happens if the individual sells the security at a loss, and their spouse or a company they control buys a substantially similar security within 30 days.
• The wash-sale rule prevents taxpayers from deducting a capital loss on the sale against the capital gain. 

If you have a Wash Sale you cannot deduct the initial loss.  The value of the loss will be added to the cost basis of the second option that you purchased.