Are Prediction Markets Legal in Washington?

Washington has the strictest interpretation of gambling law of any US state. Online gambling — including peer-to-peer poker — is a Class C felony under RCW 9.46.240 (opens in a new tab). Against that backdrop, Washington Attorney General Nick Brown filed a lawsuit on March 27, 2026 against Kalshi, alleging the platform "violates state law by operating and advertising an online platform" for illegal gambling. Robinhood has since countersued Washington in federal court, and the December 9, 2025 Washington State Gambling Commission warning (opens in a new tab) declared that prediction markets are "not authorized" in Washington.

This is the most aggressive multi-front state action against prediction markets currently in progress in the United States. As of April 21, 2026, prediction-market platforms were still accessible to Washington addresses; since August 19, 2026 Kalshi has blocked sports and several other contract types there under a court order, and the legal posture is the most uncertain of any major US prediction-market state.

Why Washington Is Uniquely Hostile

Three structural factors:

1. The country's broadest gambling statute. RCW 9.46 criminalizes essentially any online wagering not specifically authorized. Washington is one of only two states (Utah being the other) where any form of online gambling is a felony.
2. A powerful tribal gaming coalition. Washington has 29 federally recognized tribes operating tribal gaming under IGRA compacts. The Tulalip, Muckleshoot and Puyallup tribes have aggressively defended their gaming exclusivity. Sports betting in Washington is currently legal only on tribal lands (in-person), giving tribes effective monopoly control.
3. A consumer-protection-led AG. Nick Brown was elected on a consumer-protection platform. His office's news release on Kalshi emphasizes lack of state responsible-gaming protections and the 18+ age threshold.

What Washington Residents Can Trade Right Now

A Washington court has since ordered Kalshi to block several contract types in the state (in effect from August 19, 2026); commodities, climate, economics and finance markets remain open there.

• Robinhood: Operational. Now actively suing the state to maintain access.
• Polymarket US: Operational, funded in US dollars.
• OG.com: Operational.
• DraftKings Predictions / FanDuel Predicts / Fanatics Markets: Not available in Washington — these companies hold tribal-partnered sportsbook licenses elsewhere and have voluntarily geofenced their predictions products from WA.

Volume is meaningful but lower than peer states. Kalshi reports Washington as one of its top-15 states by user count, despite the litigation.

Best Prediction Market Platforms for Washington Residents

Kalshi — Primary target of AG Brown's lawsuit. Sports, elections, politics, entertainment, culture, tech/science and mention markets blocked by court order since August 19, 2026. Sports, politics, macro, crypto. CFTC Designated Contract Market.

Zero commission.

Polymarket US — Available, funded in US dollars, deepest crypto and political markets.

OG.com — Available, sports-focused, low fees.

Novig — Available in Washington: deposit $10, get $50 in trade credits with code RANKPREDICTS.

Rebet — Available in Washington: 100% purchase match up to $100 with code RANKPREDICTS.

Chalkboard, Sleeper — Check each app for Washington availability.

Eligibility Checklist for Washington Residents

• 18+ on CFTC-regulated platforms.
• Government ID + SSN for KYC.
• Be aware that AG Brown's lawsuit, if successful, could result in platforms withdrawing from Washington with little notice. Avoid keeping unnecessarily large balances.
• Funding from a US bank account or debit card. Polymarket US funds in dollars inside its app.

Tax Treatment for Washington Residents

Washington has no state income tax, which is materially favorable for prediction-market traders compared to California (13.3%) or New York (10.9%). Federal treatment is unsettled: the IRS↗ (opens in a new tab) hasn't issued guidance on event contracts, and tax professionals argue for gambling income, capital gains or Section 1256 (60/40) treatment. Consult a tax professional — the litigation creates additional complexity around how Washington might ultimately classify gains if the AG prevails.

What could change the status

Dates we are watching: Nevada's responses to the Robinhood and Crypto.com Supreme Court petitions are now due November 13 and 16, 2026 (both extended in October), and Kalshi's response to New Jersey's petition is due November 9, 2026 (deadlines can be extended); the earliest the Supreme Court could act on the petitions is a conference in December 2026 or January 2027 (our estimate, not a scheduled date); the Ninth Circuit has not yet decided Kalshi's request for a rehearing by the full court. We re-check this page when any of these happen and log the change above.

Sources

• Washington Attorney General: Washington sues online betting platform Kalshi for illegal gambling (opens in a new tab)
• Washington State Standard: WA clashes in court with prediction market platforms Kalshi and Robinhood (opens in a new tab)
• The Seattle Times: Kalshi 'prediction market' violates WA antigambling laws, AG says (opens in a new tab)
• KING-5: Robinhood sues Washington after state crackdown on Kalshi (opens in a new tab)

Status in Washington as of October 3, 2026

Platform	Status	Why (source)	Welcome offer in Washington
Kalshi	Sports contracts blocked by court order	Under a Washington court preliminary injunction, Kalshi has blocked sports, election, politics, entertainment, culture, tech/science and mention contracts for Washington users since Aug 19, 2026; commodities, climate, economics and finance markets remain open. (source (opens in a new tab))	Not valid here
Polymarket US	Available, dispute pending	Polymarket US accepts Washington residents; a Washington court injunction led Kalshi to block sports, election and several other categories from Aug 19, 2026; Washington is in the Ninth Circuit. (source (opens in a new tab))	Valid: Deposit $10 get a $25 Trading Bonus!
ProphetX	Available, dispute pending	ProphetX accepts Washington residents; a Washington court injunction led Kalshi to block sports, election and several other categories from Aug 19, 2026; Washington is in the Ninth Circuit. (source (opens in a new tab))	Valid: Trade $50, Earn $75!
OG (by Crypto.com)	Available, dispute pending	OG accepts Washington residents; a Washington court injunction led Kalshi to block sports, election and several other categories from Aug 19, 2026; Washington is in the Ninth Circuit. (source (opens in a new tab))	Valid: Trade $25 Get $50 in Rewards! (New users only)
Novig	Available, dispute pending	Novig accepts Washington residents; a Washington court injunction led Kalshi to block sports, election and several other categories from Aug 19, 2026; Washington is in the Ninth Circuit. (source (opens in a new tab))	Valid: Deposit $10 Get $50 in Trade Credits!
Rebet	Available, dispute pending	Rebet is a sweepstakes app, not a CFTC-regulated exchange; its sweepstakes rules include Washington. (source (opens in a new tab))	Valid: Get a 100% purchase match up to $100!

What changed (newest first)

• Sep 11, 2026 (federal) — Crypto.com asks Supreme Court to review Ninth Circuit ruling (No. 26-344). Source: Supreme Court of the United States, docket No. 26-344 (opens in a new tab)
• Sep 10, 2026 (federal) — Kalshi seeks Ninth Circuit rehearing; Robinhood petitions Supreme Court. Source: Sports Betting Dime (opens in a new tab)
• Sep 2, 2026 (federal) — New Jersey asks U.S. Supreme Court to review Kalshi preemption ruling. Source: New Jersey Office of the Attorney General (opens in a new tab)
• Aug 28, 2026 (federal) — Ninth Circuit rules for Nevada regulators in Kalshi case. Source: U.S. Court of Appeals for the Ninth Circuit (opinion, No. 25-7516) (opens in a new tab)
• Aug 19, 2026 — Kalshi begins blocking certain event contracts in Washington. Following a King County Superior Court order, Kalshi began blocking sports, election and several other categories of contracts for Washington users, with full geofencing required by September 2. Source: Sports Betting Dime (opens in a new tab)
• Jul 22, 2026 — Washington judge grants preliminary injunction against Kalshi. King County Superior Court Judge John McHale found the state likely to succeed on claims that parts of Kalshi's offering violate the Washington Gambling Act and granted a preliminary injunction. Source: Sports Betting Dime (opens in a new tab)
• Apr 6, 2026 (federal) — Third Circuit sides with Kalshi against New Jersey regulators. Source: U.S. Court of Appeals for the Third Circuit (opinion, No. 25-1922) (opens in a new tab)
• Mar 27, 2026 — Washington Attorney General sues Kalshi. Attorney General Nick Brown filed a lawsuit alleging Kalshi violates the state Gambling Act and Consumer Protection Act, seeking to stop its operations in Washington and recover losses and penalties. Source: Washington State Attorney General (opens in a new tab)

Prediction markets in other states

• Alaska
• California
• Colorado
• Connecticut
• Florida
• Hawaii
• Illinois
• Kansas
• Maryland
• Massachusetts
• Minnesota
• Nebraska
• New Hampshire
• New Jersey
• New York
• North Dakota
• Oregon
• Pennsylvania
• Rhode Island
• Texas
• Utah
• Vermont
• Virginia
• Washington
• Wyoming
• Alabama
• Arizona
• Arkansas
• Delaware
• Georgia
• Idaho
• Indiana
• Iowa
• Kentucky
• Louisiana
• Maine
• Michigan
• Mississippi
• Missouri
• Montana
• Nevada
• New Mexico
• North Carolina
• Ohio
• Oklahoma
• Puerto Rico
• South Carolina
• South Dakota
• Tennessee
• Washington DC
• West Virginia
• Wisconsin

§ References & Sources

1. Commodity Futures Trading Commission (CFTC) (opens in a new tab)— U.S. federal regulator
2. CFTC Designated Contract Markets list (opens in a new tab)— CFTC
3. 26 U.S. Code § 1256 — Section 1256 contracts marked to market (opens in a new tab)— Cornell Law / U.S. Code
4. IRS Form 6781 — Gains and Losses From Section 1256 Contracts (opens in a new tab)— Internal Revenue Service
5. National Council on Problem Gambling — 1-800-GAMBLER (opens in a new tab)— NCPG

Frequently asked questions

Are prediction markets legal in Washington?

We don't give legal verdicts, but here is the status as of October 3, 2026: Kalshi: sports contracts blocked by court order (other markets stay open); Polymarket US, ProphetX, OG and Novig: Available, dispute pending. A Washington court injunction led Kalshi to block sports, election and several other categories from Aug 19, 2026; Washington is in the Ninth Circuit. Nationally, federal appeals courts are split on sports event contracts, all at the preliminary-injunction stage, and three Supreme Court petitions are pending; none has been granted.

Can I use Kalshi in Washington?

Status as of October 3, 2026: Sports contracts blocked by court order. Under a Washington court preliminary injunction, Kalshi has blocked sports, election, politics, entertainment, culture, tech/science and mention contracts for Washington users since Aug 19, 2026; commodities, climate, economics and finance markets remain open. We do not show Kalshi's welcome offer for Washington. Kalshi's minimum age is 18; we recommend 21+.

What has Washington done about prediction markets?

A Washington court injunction led Kalshi to block sports, election and several other categories from Aug 19, 2026; Washington is in the Ninth Circuit. Most recent entries in our timeline: Aug 19, 2026: Kalshi begins blocking certain event contracts in Washington; Jul 22, 2026: Washington judge grants preliminary injunction against Kalshi; Mar 27, 2026: Washington Attorney General sues Kalshi. Each entry above links to its source.

What could change the status in Washington?

Dates we are watching: Nevada's responses to the Robinhood and Crypto.com Supreme Court petitions are now due November 13 and 16, 2026 (both extended in October), and Kalshi's response to New Jersey's petition is due November 9, 2026 (deadlines can be extended); the earliest the Supreme Court could act on the petitions is a conference in December 2026 or January 2027 (our estimate, not a scheduled date); the Ninth Circuit has not yet decided Kalshi's request for a rehearing by the full court. We re-check this page when any of these happen and log the change above.