Chapter 14: Taxes — The Silent Partner

Every trade has a silent partner who takes a cut, never takes a loss, and never forgets: the tax code. High-turnover AI strategies, bots, signal services, agentic traders, generate tax consequences that can quietly erase their entire edge. This chapter is the math the marketing never shows.

I'm a planner, not a CPA. Tax law is fact-specific and it changes. Treat this as the map of the territory, then talk to a tax professional before running anything high-turnover in a taxable account.

Short-term vs. long-term: the first hurdle

Hold a stock more than a year: long-term capital gains, taxed at 0%, 15%, or 20% depending on income. Hold it a year or less: short-term, taxed as ordinary income, up to 37% at the federal level, plus state tax.

AI trading strategies are overwhelmingly short-term. Bots don't hold for thirteen months out of tax elegance. They trade on signals measured in minutes to weeks. So the real hurdle isn't beating the market. It's beating the market after paying ordinary-income rates on nearly every gain. A strategy that earns 12% pre-tax and keeps 8% after tax didn't beat a buy-and-hold investor earning 10% taxed at 15%. Model the after-tax edge, not the pre-tax fantasy. Almost nobody does this calculation, which is exactly why it matters.

Wash sales: the bot's favorite trap

The wash-sale rule: if you sell a security at a loss and buy a "substantially identical" security within 30 days before or after the sale, the loss is disallowed for current tax purposes. The disallowed loss gets added to the replacement shares' cost basis, deferred rather than destroyed, except inside IRAs, where it's permanently destroyed.

Three things make this brutal for AI trading:

  1. It applies across all your accounts, including your spouse's. Your bot in the taxable account and your 401(k)'s index fund can trigger each other's wash sales. The IRS sees one taxpayer, not one brokerage login.
  2. High-turnover bots can generate thousands of wash sales a year, turning tax reporting into a reconciliation nightmare. Errors on 1099-Bs across multiple accounts are common, and you're responsible for getting it right.
  3. The IRA trap is permanent. If your bot's wash sale involves replacement shares bought inside an IRA, the loss isn't deferred. It's gone forever. Running an aggressive strategy across taxable and retirement accounts without understanding this is how people donate losses to the Treasury.

Advisers already warn that agentic trading platforms can generate tax bills that wipe out any extra return, and many of these platforms offer no tax reporting beyond the raw 1099. The gains are yours to celebrate. The paperwork is yours to untangle.

Netting, limits, and carryforwards

The mechanics, briefly: capital losses offset capital gains dollar for dollar. If losses exceed gains, up to $3,000 per year can offset ordinary income ($1,500 if married filing separately). The remainder carries forward indefinitely. This is why tax-loss harvesting, the robo-advisors' beloved feature from Chapter 6, works. It banks losses against future gains systematically, without the chaos of a day-trading bot.

One crypto footnote: as of 2026, the wash-sale rule does not apply to cryptocurrency. Crypto is treated as property, not a security, for this purpose. Crypto-to-crypto trades are still taxable events, and like-kind exchange treatment doesn't apply. Congress has discussed closing the crypto wash-sale gap for years. Don't build a strategy on a loophole that might close.

The active-trader election

There's a special tax status, the Section 475 mark-to-market election, that lets qualifying active traders treat gains and losses as ordinary and escape the wash-sale rule. It sounds like a solution. In practice, qualifying is fact-specific and restrictive. The IRS looks at frequency, holding periods, and whether trading is truly your business. The election is binding, and getting it wrong is worse than not electing. This is firmly "hire a CPA" territory, not "read a chapter" territory.

The planner's tax rule for AI trading

Before funding any AI trading strategy in a taxable account, answer this in writing: what is the strategy's expected after-tax return, and what would the same capital earn in a tax-efficient buy-and-hold portfolio? If you can't answer, if the vendor can't answer, you're not evaluating an investment. You're admiring a backtest.

Taxes are the silent partner. In high-turnover strategies, they're often the majority partner. Plan accordingly.