Polymarket US vs. Robinhood: Prediction Markets Compared

Prediction markets used to mean one thing: Polymarket, a crypto-native exchange most Americans couldn’t legally use. That’s no longer the picture. Polymarket now runs a separate, CFTC-regulated US entity, and Robinhood — a mainstream brokerage most people already have an account with — has built prediction-market trading into its app too. Both let you trade event contracts that pay $1 if you’re right and $0 if you’re wrong. The way they charge you to do it, and the sign-up offer that gets you started, are different enough that “which one should I use” doesn’t have one answer.

What each platform actually is

Polymarket US is a dedicated prediction-market exchange, run by QCX LLC as a CFTC-regulated Designated Contract Market. Trading event contracts is the entire product. It’s a separate company from the international site at polymarket.com, which US residents can only use to close existing positions, not open new ones — the two-sites situation is confusing enough that we’ve written a full explainer on why there are two Polymarket sites.

Robinhood is a general brokerage — stocks, options, crypto — that added event contracts as one more product inside an account you might already use for something else. For most of its prediction-markets history, Robinhood routed those contracts to Kalshi, a separate CFTC-regulated exchange, and split a per-contract fee with it. As of June 2026, Robinhood began routing some contracts instead to Rothera, a CFTC-licensed exchange and clearinghouse it operates through a joint venture with market maker Susquehanna International Group. Robinhood’s own announcement names World Cup and professional baseball contracts as the first to move to Rothera, with more planned; contracts not yet moved still route through Kalshi.

That distinction matters because it means “Robinhood” isn’t one fee structure or one counterparty — which market you’re trading can determine which exchange is actually clearing it.

Fees: a formula vs. a capped commission

Polymarket US charges takers a formula tied to the contract’s price: 0.0695 × contracts × price × (1 − price). The dollar fee peaks at a 50¢ contract and shrinks toward the edges, but as a share of what you’ve actually staked, cheap long-shot contracts pay the larger bite. The exact numbers at 10¢, 50¢ and 90¢ are worked out in our breakdown of the Polymarket US fee formula, sourced from Polymarket’s own fee schedule.

Robinhood’s current commission, per its own June 2026 announcement, “varies based on the price of the contract and the size of the order” but is capped so it “never exceeds $0.01 per contract.” That’s a flat ceiling rather than a curve: a 100-contract trade can cost at most $1 in Robinhood’s own commission, regardless of price, though the exchange clearing the trade (Kalshi or Rothera) can add its own separate per-contract fee on top. Robinhood Gold subscribers get a further discount — the announcement cites up to 50% less per trade than non-Gold customers.

The two aren’t directly comparable dollar-for-dollar, because Polymarket’s number is the whole fee and Robinhood’s is only Robinhood’s own cut before any exchange fee is added. The honest comparison is: Polymarket’s fee is a known, published curve you can calculate in advance from one source; Robinhood’s all-in cost depends on which exchange ends up clearing that specific contract, and that routing isn’t something you choose. If knowing the exact cost before you trade matters to you, Polymarket’s formula is the one you can actually run the numbers on without guessing.

Sign-up offers: credit you can’t cash out vs. stock you can

Polymarket US’s referral offer gives new users $25 in trading credit after a $10 deposit. The catch, covered in full in our breakdown of the $25 credit: it’s non-withdrawable. You can trade with it and keep any winnings above it, but the $25 itself never becomes cash, win or lose.

Robinhood’s free-stock offer gives new users an actual share of stock — guaranteed at least $5, with a 1-in-1,000 shot at $200 — for linking a bank account, no deposit required. Once the standard holding periods pass (sellable after 3 trading days, the cash value withdrawable after 60), it’s unambiguously yours. The realistic expected value is close either way — most people land near $5 to $25 on either platform — but the shape of what you’re given is opposite: Polymarket hands you a stake you must risk to realize any value; Robinhood hands you an asset you keep by doing nothing further.

What you can actually trade

Polymarket US is prediction markets and nothing else — politics, sports, economics, culture, and whatever else the exchange lists as a contract. Robinhood’s event contracts sit alongside everything else in a normal brokerage account: stocks, ETFs, options, and crypto, with prediction markets as one more tab. If you already want a brokerage account for ordinary investing and prediction markets are a side interest, Robinhood means one login instead of two. If prediction markets are the main thing you’re there for, Polymarket US’s narrower, dedicated interface is built around that one job.

The bottom line

Neither platform is “cheaper” in every situation. Polymarket US publishes one formula that applies to every trade, which makes it the easier one to calculate costs on ahead of time. Robinhood caps its own commission at a cent a contract but adds a separate, routing-dependent exchange fee on top, and which exchange you land on isn’t up to you. On the sign-up side, Robinhood’s free stock is the safer bet if you want something guaranteed to keep; Polymarket’s $25 is a stake worth taking if you’re going to trade anyway. Most people interested in prediction markets end up checking prices on both before placing a real-money trade — the fee structures differ enough that the same contract isn’t always the same price to open.

Our hubs for Polymarket US and Robinhood have the current referral codes and the dates we last checked each against the platform’s own terms, under the standard explained on how we verify.