Can you run arbitrage between Kalshi and PredictIt?

Not really. PredictIt has no public trading API, so there's no way to place orders programmatically or execute both legs of a trade near-simultaneously. Combined with PredictIt's narrow, mostly US-politics market catalogue and limited overlap with Kalshi's listings, the two platforms don't support the cross-platform strategy this site covers the way Kalshi and Polymarket do.

Does PredictIt have a position limit?

Yes. PredictIt applies a fixed cap on how much any single trader can hold in a given contract, tied to the boundaries of its CFTC research exemption. Kalshi doesn't impose an equivalent blanket cap — position size there is constrained by available liquidity and Kalshi's own risk limits instead.

Is Kalshi regulated the same way as PredictIt?

No. Kalshi is a CFTC-designated contract market, the same category as CME and CBOE, with explicit support for algorithmic trading. PredictIt operates under a narrower research exemption tied to an academic partner — a status that has faced legal challenges over the years rather than the settled regulatory footing Kalshi has.

Kalshi vs PredictIt (2026) | Arbitrage Agent

Kalshi and PredictIt are both US-facing prediction market platforms, but they're built on almost opposite foundations. Kalshi is a CFTC-designated exchange with no fixed position cap and a public trading API. PredictIt runs under a narrower regulatory exemption, caps how much you can put into any single contract, and has never offered the kind of API access that automated trading — arbitrage included — depends on.

If you're choosing between the two, or wondering whether PredictIt can slot into a cross-platform arbitrage strategy the way Polymarket does alongside Kalshi, the short answer is: for the strategy this site covers, it can't. Here's why, in detail.

What PredictIt actually is

PredictIt has been running since 2014, predating both Kalshi and Polymarket by years, and it built much of the modern retail prediction-market audience before either of them existed. It's operated in partnership with Victoria University of Wellington under a research exemption from the CFTC — not as a designated contract market the way Kalshi is. That distinction isn't cosmetic: it's the reason PredictIt caps position sizes and doesn't offer the programmatic access that Kalshi treats as a first-class feature.

Regulatory status: designated exchange vs research exemption

Kalshi is a CFTC-designated contract market — the same regulatory category as CME and CBOE. It explicitly permits algorithmic and API-driven trading and publishes documented endpoints for exactly that purpose. PredictIt's legal footing is narrower and has been contested over the years; its research exemption has faced legal challenges, and the platform has at times continued operating under court proceedings rather than the kind of settled regulatory status Kalshi holds. If a stable, long-term regulatory foundation for an automated strategy matters to you, that's a meaningful difference before you even look at fees or limits.

Position limits — the ceiling that actually matters

This is where the two platforms diverge hardest. Kalshi doesn't impose a blanket per-contract cap the way PredictIt does; your position size is constrained by available liquidity and Kalshi's own risk controls, not a fixed dollar ceiling applied per user per contract. PredictIt, by contrast, has always applied a hard cap on how much any single trader can hold in a given contract — a limit that exists specifically to keep the platform within its research-exemption boundaries. For a strategy built around deploying meaningful capital across many markets, that cap is the first thing that rules PredictIt out at scale.

Fees: what each platform actually takes

PredictIt's fee model has always looked different from a standard exchange: it takes a cut of trading profits when you sell a winning position, and a separate cut when you withdraw funds. Combined, those two charges erode net returns in a way that's structurally different from a straightforward per-trade fee. Kalshi's fee structure is closer to a standard exchange model — a fee applied to trades, without a separate withdrawal charge layered on top. For any strategy where you're calculating a precise net edge before executing — which is the entire point of arbitrage — a platform that takes an additional cut on withdrawal makes the real cost of trading materially harder to model.

Can you automate either platform?

This is the question that decides whether PredictIt belongs in an arbitrage strategy at all. Kalshi publishes a documented REST and WebSocket API built specifically for programmatic order placement and real-time order book access — the same kind of infrastructure Polymarket offers, which is what makes Kalshi/Polymarket cross-platform arbitrage possible in the first place. PredictIt has no equivalent. There's no official trading API, no documented endpoint for placing orders programmatically, and no first-party support for the near-simultaneous dual-leg execution that arbitrage requires. Any attempt to automate PredictIt means scraping a website that was never built for it — fragile, against the platform's terms, and a poor foundation for anything involving real capital.

Liquidity and market coverage

PredictIt's catalogue leans heavily toward US politics — narrower than Kalshi's, which spans politics, macroeconomics, crypto and more. Liquidity on PredictIt's most active political contracts can be reasonable, but it doesn't match the breadth of markets, or the depth on non-political categories, that Kalshi and Polymarket carry together. For a cross-platform strategy, what matters most is the overlap of markets listed on both venues at once — and that overlap between Kalshi and Polymarket is what the entire arbitrage strategy on this site is built on. PredictIt sits largely outside it.

So, which platform is better?

For a US resident who wants to trade prediction markets directionally on a single platform, Kalshi is the stronger choice on almost every dimension: no fixed position cap, a more standard fee structure, deeper and broader liquidity, and a clear regulatory category. PredictIt still has value as the platform with the longest track record on US political contracts specifically, and some traders prefer its established community for that narrow use case. But for the strategy covered on this site — buying the same event on two platforms simultaneously to lock in a spread that's fixed regardless of outcome — PredictIt doesn't work. There's no API to automate execution, no meaningful overlap of markets with Kalshi or Polymarket, and a position cap that limits any single contract regardless of the edge available.

Getting started

If you're weighing Kalshi against Polymarket instead — the pair cross-platform arbitrage actually runs on — see our full fee and liquidity comparison. Arbitrage Agent scans thousands of matched market pairs between Kalshi and Polymarket, calculates net edge after both platforms' fees, and alerts you the moment a real spread opens. Join the waitlist for early access, or see the plans starting at $29/month for dry-run signal tracking.

Key terms: Cross-Market Arbitrage · Spread · CLOB (Central Limit Order Book)

Kalshi vs PredictIt: Fees, Limits and Which Is Better in 2026