How Are Event Contracts Taxed?

How Event Contracts Are Taxed on Kalshi and Polymarket

Event contracts are taxed differently depending on which platform you trade, what instrument you hold, and where you live — and the answer changes the moment you cross from a regulated exchange like Kalshi into an offshore or crypto-settled venue like Polymarket. If you trade prediction markets with any real position size, tax treatment is not a footnote. It affects your realized return as directly as slippage or a bad entry, and it's a variable you should be modeling before you place the trade, not after you file. This article walks through how the IRS currently treats event contracts, why Kalshi and Polymarket create different paperwork trails, what forms you'll actually see, and where the unresolved gray areas sit. None of this is a substitute for a CPA who has looked at your specific trading pattern, but you should walk into that conversation informed.

Kalshi vs Polymarket 2026: Why Tax Treatment Diverges

The single biggest driver of your tax outcome is jurisdiction and regulatory wrapper, not the underlying event you're trading. Kalshi is a CFTC-regulated designated contract market operating inside the U.S. financial system, which means it issues U.S. tax forms and reports to the IRS the way a futures broker does. Polymarket, by contrast, settles in USDC on a public blockchain and — for U.S. persons — operates in a legally murkier space, with no equivalent domestic reporting infrastructure. That structural gap is the reason the two platforms produce completely different paper trails at tax time, even when you're trading the exact same election or macro event on both. For a side-by-side breakdown of the regulatory and product differences beyond tax, see Kalshi vs Polymarket 2026.

On Kalshi, every contract you hold is a "yes/no" binary option cleared through a regulated exchange, and the exchange has both the obligation and the technical infrastructure to report your activity. On Polymarket, you're interacting with a smart contract, and there is no broker in the traditional sense standing between you and the IRS — the reporting burden sits entirely on you.

Section 1256 Contracts: The Core Tax Question for Event Contracts

The pivotal question for Kalshi-style event contracts is whether the IRS treats them as "Section 1256 contracts," a category historically reserved for regulated futures, foreign currency contracts, and certain options. Section 1256 treatment is significant because it triggers two distinct effects: mark-to-market accounting (you're taxed on unrealized gains at year-end, even on positions you haven't closed) and the 60/40 rule, where 60% of gains are taxed at long-term capital gains rates and 40% at short-term rates, regardless of how long you actually held the position.

Kalshi has historically issued 1099 forms consistent with 60/40 treatment for many of its contracts, though the IRS has not issued blanket, contract-by-contract guidance covering every event type Kalshi lists — sports, weather, economic data, and political outcomes can sit in different interpretive buckets. This is an area where the regulatory landscape has moved quickly and where prior-year treatment isn't a guarantee of future treatment. Don't assume last season's 1099 categorization will carry forward unchanged; verify with your preparer each filing year.

How Kalshi Works: 1099 Forms and Reporting You'll Actually Receive

If you trade on Kalshi as a U.S. resident, expect to receive a 1099 — typically a 1099-B or a form reflecting aggregate gains and losses, depending on Kalshi's current reporting methodology for the tax year. This is functionally similar to what you'd get from a futures or options broker: the exchange calculates your realized (and, if 1256-eligible, mark-to-market) gains and sends both you and the IRS a copy. That means your Kalshi activity is already visible to the IRS independent of whether you personally report it — there's no ambiguity about whether the government sees the data. For a primer on how contracts, settlement, and margin work mechanically on the platform before you get to the tax layer, read How Kalshi Works.

Because the reporting is automated, your practical job on Kalshi is reconciliation: matching your own trade log against the 1099 Kalshi issues, flagging discrepancies early, and keeping records of your specific entries and exits by market ticker in case you need to substantiate short-term versus long-term splits or dispute a reporting error.

Polymarket Tax Treatment: Self-Reporting and Capital Gains

Polymarket does not currently issue U.S. tax forms to traders, which shifts the entire compliance burden onto you. For most U.S. taxpayers, gains from Polymarket positions are best treated as either capital gains (if the position resembles a property disposition) or, depending on your trading frequency and how aggressively you'd defend the position under audit, potentially other income treatment. There is no official 60/40 blended rate applied automatically the way there can be with Kalshi's 1256-eligible contracts — you're working from your own transaction history, denominated in USDC, and converting each trade to USD fair market value at the time of the transaction.

This self-reporting requirement is compounded by the crypto layer: moving USDC in and out of a wallet, bridging between chains, or holding USDC that appreciates or depreciates relative to USD can itself create separate taxable events unrelated to the prediction market position itself. Traders who run size on Polymarket typically need a crypto-aware tax tool or CPA who can trace wallet activity, not just exchange statements — a materially heavier lift than the Kalshi 1099 workflow.

Wash Sales, Losses, and Netting Across Both Platforms

A practical question that comes up constantly: can you net a loss on a Kalshi weather contract against a gain on a Polymarket election contract? Generally, yes, in the sense that both ultimately flow into your overall capital gains picture, but the character of each gain or loss (1256 mark-to-market versus straight capital gain) doesn't automatically blend into a single rate — they're calculated on different schedules and forms, then combined at the return level. The wash sale rule, which disallows a loss deduction when you repurchase a substantially identical position within 30 days, was written for stocks and securities and its application to event contracts is unsettled; don't assume it doesn't apply just because these are binary contracts rather than shares.

This is also where position-sizing discipline pays off at tax time, not just at risk-management time. Traders who chase correlated positions across both platforms — for instance the same macro release framed slightly differently on Kalshi and Polymarket — often generate a tangle of short-term gains and losses that's expensive to reconstruct in April if it wasn't logged in real time. If you're newer to reading the actual payoff structure of these contracts before worrying about tax treatment, start with How to Read Prediction Market Odds.

Best Prediction Market 2026: Choosing a Platform With Tax Efficiency in Mind

Tax treatment is a legitimate input into platform selection, not just fees, liquidity, and market breadth. If you value automated 1099 reporting, a clear U.S. regulatory wrapper, and (for many contract types) potential 60/40 treatment, Kalshi's structure is generally more tax-administratively friendly for a U.S. trader who wants clean paperwork. If you're prioritizing market breadth, faster listing of niche or international events, and you're comfortable managing your own crypto-denominated tax records, Polymarket's tradeoffs may still make sense for your strategy — you're just taking on more bookkeeping. For a broader comparison across platforms including fee structure and market selection, see Best Prediction Market 2026.

Either way, the platform choice should be made with full knowledge of the reporting burden it creates, because that burden is a real, recurring cost of running the strategy — not a one-time setup fee.

How PillarLab AI Fits Into This

PillarLab AI doesn't file your taxes, but it does help you trade with the discipline that makes tax season tractable instead of chaotic. The platform runs a structured 9-pillar analysis across every market you're evaluating — pulling real-time Kalshi and Polymarket data, cross-referencing liquidity, pricing dislocations, and event-specific signal quality — so you're entering positions with a documented, repeatable rationale rather than an ad hoc gut call. That structure matters at tax time too: when you can point to a clear entry thesis and a timestamped edge-detection signal for every position, reconciling your trade log against a Kalshi 1099 or your own Polymarket wallet history is far less painful than reconstructing intent months later.

Because PillarLab AI tracks positions across both Kalshi and Polymarket in one place, it also gives you a consolidated view of exposure across the platforms with genuinely different tax treatments — useful when you're deciding whether a given trade is worth the extra bookkeeping load a Polymarket position carries relative to a Kalshi one. The 9-pillar framework flags edge quality, not tax category, but a disciplined, well-documented process is the foundation every good CPA conversation is built on. If you're trading event contracts across multiple venues and want your analysis and your recordkeeping to be equally rigorous, PillarLab AI is built for that workflow.

Frequently Asked Questions

Are Kalshi event contracts taxed as capital gains?

Many Kalshi contracts have historically received Section 1256 treatment, meaning gains are marked to market and split 60% long-term, 40% short-term regardless of holding period, rather than standard capital gains rules.

Does Polymarket send tax forms to U.S. traders?

No. Polymarket does not currently issue 1099s or equivalent U.S. tax documents, so you are responsible for tracking and reporting your own gains and losses from wallet activity.

What form does Kalshi use to report gains?

Kalshi typically issues a 1099-style form reflecting realized and, where applicable, mark-to-market gains for the tax year, similar to reporting from a regulated futures broker.

Can I net losses between Kalshi and Polymarket positions?

Generally yes at the overall return level, but each platform's gains and losses are calculated under different rules (1256 mark-to-market versus standard capital gains) before combining.

Do wash sale rules apply to event contracts?

This remains an unsettled area. The rule was designed for securities, and its application to binary event contracts hasn't been definitively clarified by the IRS, so conservative treatment is advisable.

Trade event contracts with a documented, repeatable edge across both platforms: Start free with 10 credits.