Trading involves sales. A broker will sell off one stock to buy another. The fact that you did not get the money is irrelevant. Report your 1099-B exactly as it appears. You must report all your income. If you had a gain, it is taxable. If it is a long-term gain, it may or may not be taxable depending on the rest of your income.
If you had a loss, you can take up to $3,000 of it in 2019 and carry the rest to 2020.
