Do I Owe Tax on Trades If I Never Withdraw the Money?

Under US federal tax rules, the sale is what counts.

Sell a position for more than its cost basis and you have a realized gain. It belongs to the tax year in which the sale happened, and it makes no difference to the IRS whether the proceeds sit in the account as cash, go straight into the next trade the same afternoon, or are wired out to your bank, because a withdrawal is only a movement of your own money from one place to another.

Losses work the same way. They count in the year of the sale. They can offset gains.

The year itself is generally fixed by the trade date. Under T+1 settlement the cash arrives a business day after you sell, so a sale on the last trading day of December can settle in January and still, as a rule, belong to December’s tax year; confirm how your own year-end trades are treated with a tax professional.

A year of trades, netted

Say you trade in an ordinary taxable account and never take a cent out. You close five positions.

All 2,300 is reportable. Every dollar stayed in the account.

That changes nothing.

How the gain is treated also depends on how long you held each position. Short-term and long-term results are taxed differently, and the line between them is the holding period. The IRS publishes the rates each year, and a tax professional can tell you which apply to your return.

Wash sales can defer a loss

Under the IRS wash-sale rule, a loss is disallowed when you buy substantially identical shares in the 30 days on either side of the losing sale. Trade D’s 1,600 is not gone. It is carried into the cost basis of the replacement shares, and it comes back into your figures when those shares are eventually sold, which may be in a later tax year, so a trader who keeps re-entering the same few names can end a year with a reported gain well above what the account actually made.

The wash sale page has the detail. The wash-sale window calculator shows the dates for any sale.

Retirement accounts are different

Trades inside an IRA or a 401(k) are generally not taxed as they happen. Tax applies under that account’s own rules. For many accounts that means at withdrawal; some types can be tax-free if their conditions are met.

The rules vary by account type. The IRS publications on retirement plans set them out.

Holding both kinds of account adds a wrinkle worth raising with whoever prepares your return: a purchase in the retirement account can still interact with a loss taken in the taxable one under the wash-sale rule, even though the retirement account itself never reports a gain or loss on the trade.

What your broker sends you

Early the following year, your broker issues Form 1099-B for a taxable account. It lists each sale and its proceeds. For most shares it also shows cost basis and the wash-sale adjustments the broker can see. The IRS gets a copy.

The form has limits. Those, and everything else worth filing, are in what records a trader should keep for taxes.

One practical point. Because the tax is owed for the year whether or not you withdraw, a good trading year can mean making estimated tax payments during that year under IRS rules, and the question of whether you need to, and when, depends on the rest of your income and withholding, so raise it with a tax professional well before the year ends.