Capital Gains Tax?

You keep track of the profit or loss you realize when you sell. Until you close out your position in a stock or bond or mutual fund/ETF, you have no profit or loss.

The broker can provide you with purchase and sale information, including dates of, along with any costs you incurred in buying/selling. You use this information to complete Form 8949 and Schedule D, and that is how you report your gains and losses on your 1040.

Before one invest in anything, they should know what they're doing, how to do it, why they're doing it, AND understand the rules for what they're trying to do. - You're not there yet.

YES, you should keep track of your tax liabilities, not only including profits but also losses. It's your responsibility to report ALL taxable events not your broker's

Broker's have a legal responsibility to provide you with a record of ALL your transactions but not the profits/losses from such transactions

Brokers will provide you with year end numbers but you are ultimately responsible for reporting such to the taxing agencies.

You will receive a 1099B form sometime in mid February that will show all your sales and basis info for the year.

You'll get a "1099" form at the end of the year. It's most useful to get this in an electronic form that can be read directly into tax preparation software like TurboTax.

Be sure to google the difference between long-term and short-term capital gain.

Using a broker, you should get a summary at the end of the year...

The broker keeps track and sends you a statement in January of all the transactions from the year before, showing your losses and gains.