Start with the product behind the name. These three profiles help you find the primary sources and understand what to compare.
Sources reviewed
An introductory selection, not a complete directory or ranking. No paid placements or affiliate links. Recheck current rules and eligibility before relying on a platform description.
K
Kalshi
US exchange · Event contracts
Exchange
Kalshi appears as a designated contract market in the CFTC directory. Check the agreement for the precise account and product you use.
Settlement
Its market guidance describes a markets team finalizing the outcome using the contract’s specified source. Official data can affect timing.
Fees
Fees can vary by market. Some resting orders incur maker fees when executed; a limit order is not automatically fee-free.
Read first
The individual market rules, member agreement, and current fee schedule. Confirm the eligibility requirements that apply to your circumstances.
The CFTC directory lists QCX LLC doing business as Polymarket US as a designated contract market.
Product
Use the dedicated Polymarket US documentation. Its market rules, account terms, and fee schedule should be evaluated separately from the international platform.
Fees
The US fee schedule reviewed here states it took effect July 1, 2026 and covers taker fees, maker rebates, and conditional taker rebates. Check for later changes and applicable conditions.
Read first
US account requirements, the contract’s market rules, and the US fee schedule. A US brand name alone does not establish eligibility for every person or product.
This entry describes the international platform documented at docs.polymarket.com. The US exchange above is a separate product.
Resolution
Its documentation describes an oracle process with outcome proposals and challenges. The individual market’s resolution rules remain essential.
Fees
The international documentation describes taker fees that vary by market category and no maker trading fees. Funding or transfer providers may have separate charges.
Read first
Check geographic restrictions, current terms, and wallet and redemption requirements. At review, the international documentation restricts US users from opening new positions; the separate US product has its own access rules.
Four checks that matter more than the headline price.
Match the question, all the way down.
Compare the source, deadline, threshold, revisions, and exceptional outcomes. Similar headlines can describe different contracts.
Compare the quantity you could actually trade.
Use comparable timestamps and available depth. Add the relevant fees to the cost across all price levels your order would consume.
Follow the money through settlement.
Inspect custody, funding, settlement, withdrawal, and dispute procedures. An attractive entry price describes only one part of the experience.
Verify the legal entity and your access.
Check the current regulator listing and account terms for the exact product. Registration does not eliminate financial risk or settle every jurisdiction-specific question.