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 the sale happened in, and the IRS doesn’t care whether the proceeds sit in the account as cash, go straight into the next trade that afternoon, or get wired out to your bank, because a withdrawal just moves your own money from one place to another.

Losses follow the same logic: they count in the year of the sale, and they can offset gains.

The trade date generally fixes the year. 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, even though every dollar stayed in the account.

The treatment also depends on how long you held each position. Short-term and long-term results are taxed differently, and the holding period draws the line between them. 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 gets carried into the cost basis of the replacement shares. It comes back into your figures when you eventually sell those shares, which may be in a later tax year, so if you keep re-entering the same few names you can end a year with a reported gain well above what the account actually made.

The wash sale page has the detail. For the dates on any sale, use the wash-sale window calculator.

Retirement accounts are different

Trades inside an IRA or a 401(k) generally aren’t 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 you meet their conditions.

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

If you hold both kinds of account, raise one wrinkle with whoever prepares your return: under the wash-sale rule, a purchase in the retirement account can still interact with a loss you took in the taxable one, 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 whatever 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.

Since 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. Whether you need to, and when, depends on the rest of your income and your withholding, and it’s the kind of thing to raise with a tax professional well before the year ends.