Will the California billionaire wealth tax pass?
Yes refers to: In 2026
Short Answer
1. Market Behavior & Drivers
- Since last update (~100d): Market probability for the tax to pass dropped by 11.0pp, widening our model's edge.
- Our model decreased its probability by 7.7pp, following the market's larger 11.0pp decline.
- The edge for our model over the market widened by 3.3pp due to market-led shifts.
- Confidence score remained stable at 5.0, indicating no change in data reliability.
- Proposition 40 likely fails; Governor Newsom publicly opposes citing wealth mobility concerns.
- Proposition 40 likely fails; "No" campaign shows substantial fundraising disparity.
Who Wins and Why
| Outcome | Market | Model | Why |
|---|---|---|---|
| In 2026 | 32.0% | 39.3% | Passing a California billionaire wealth tax likely faces significant political and legal challenges. |
Current Context
Sources (11)
- 1California Secretary of State Shirley N. Weber, Ph.D., Announces New Measure Eligible for November 2026 General Election Ballot. Imposes one-time tax on certain individuals and trusts. Initiative constitutional amendment and statute.:: California Secretary of Statesos.ca.gov
- 2California proposal to tax billionaires makes November ballot | AP Newsapnews.com
- 3Proposition 40 [Ballot]lao.ca.gov
- 4California billionaire tax heads to costly November ballot | Sacramento Beesacbee.com
- 5California billionaire's tax qualifies for the Nov. 3 ballotnews.ballotpedia.org
- 6California billionaire's tax qualifies for the November ballotnews.ballotpedia.org
- 7Signatures submitted for California initiative enacting one-time billionaire tax for healthcare and education funding - Ballotpedia Newsnews.ballotpedia.org
- 8Two California tax initiatives targeting personal asset taxes and special tax rules qualify for the ballot in challenge to billionaires’ tax initiative - Ballotpedia Newsnews.ballotpedia.org
- 9California voters are set to decide on 14 ballot measures this fall - Ballotpedia Newsnews.ballotpedia.org
- 10California Democrats choose populism in backing billionaire taxcalmatters.org
- 11California billionaire tax: The risks for biggest state...cnbc.com
2. Price Chart
Historical Price (Probability)
3. Market Data
Contract Snapshot
Based on the provided page content, the exact triggers for a YES or NO resolution are not specified. The market begins on November 3, 8:00 AM EST, and has a maximum payout date of November 3, 2027. No special settlement conditions are mentioned.
Available Contracts
Market options and current pricing
| Outcome bucket | Yes (price) | No (price) | Last trade probability |
|---|---|---|---|
| In 2026 | $0.32 | $0.69 | 32% |
Market Discussion
California's "One-Time Wealth Tax for State-Funded Healthcare, Education, and Food Assistance Programs Initiative," officially Proposition 40, has qualified for the November 3, 2026, general election ballot, proposing a one-time 5% tax on residents and trusts with a net worth over $1 billion [1][2][3]. While backed by SEIU-United Healthcare Workers West [4] and endorsed by California Democrats [5], the measure faces opposition from Governor Gavin Newsom, business interests, and prominent billionaires, who warn of capital flight and economic damage [4][5][6][7]. Two competing initiatives challenging the wealth tax have also qualified for the November 2026 ballot, with negotiations reported concerning their status [2][8], and as of August 6, 2026, prediction markets assign Proposition 40 a 31.5% probability of success [9].
Sources (9)
- 1California Secretary of State Shirley N. Weber, Ph.D., Announces New Measure Eligible for November 2026 General Election Ballot. Imposes one-time tax on certain individuals and trusts. Initiative constitutional amendment and statute.:: California Secretary of Statesos.ca.gov
- 2California billionaire's tax qualifies for the Nov. 3 ballotnews.ballotpedia.org
- 3California Proposition 40, One-Time Wealth Tax for State-...ballotpedia.org
- 4California proposal to tax billionaires makes November ballot | AP Newsapnews.com
- 5Despite Gov. Gavin Newsom's opposition, California Democrats endorse Prop 40 billionaire tax measure - ABC7 San Franciscoabc7news.com
- 6It’s official: California voters will weigh a one-time billionaire taxsfchronicle.com
- 7California billionaire tax: The risks for biggest state economy in UScnbc.com
- 8Two California tax initiatives targeting personal asset taxes and special tax rules qualify for the ballot in challenge to billionaires’ tax initiative - Ballotpedia Newsnews.ballotpedia.org
- 9California Billionaire Wealth Tax Odds at Prediction Marketsdefirate.com
4. Trust Index
Order book is critically thin.
Primary risk· Trade quality
Resolution quality is low (65), but Integrity averages all three scores, so the other two pull it up. Only a critically low score would cap the total.
Includes the cost to trade: a $1,000 order can't be filled here because the order book is too thin.
Weighted blend with hard caps — a critically weak safety pillar, or a severe trading anomaly, caps the total regardless of the rest. Full methodology · About the Trust Index
5. How do the competing constitutional amendments on the November 2026 ballot aim to nullify or restrict Proposition 40?
| Ballot Date | November 3, 2026 (California ballot) [1][2][3] |
|---|---|
| Target of Measures | Proposition 40 (nullify or restrict) [1][2][3] |
| Prop 40's Tax Proposal | One-time 5% tax on net worth exceeding $1 billion [1][3][4] |
Sources (6)
- 1California Proposition 40, One-Time Wealth Tax for State-...ballotpedia.org
- 2Two California tax initiatives targeting personal asset taxes and special tax rules qualify for the ballot in challenge to billionaires’ tax initiative - Ballotpedia Newsnews.ballotpedia.org
- 3Voter guide to Proposition 40: Billionaire taxcalmatters.org
- 42026 California Proposition 40en.wikipedia.org
- 5California billionaire’s tax qualifies for the November ballot; competing measures pending signature verification - Ballotpedia Newsnews.ballotpedia.org
- 6Signatures submitted for California initiatives to prohibit taxes on personal savings and assets, require audits for new special taxes, and challenge proposed billionaire tax measure - Ballotpedia Newsnews.ballotpedia.org
6. What specific campaign activities or public statements from opponents like Governor Newsom could significantly shift public opinion on Proposition 40 before the November 2026 vote?
| Governor's Stance on Prop 40 | Opposes due to concerns about [1] |
|---|---|
| Governor's Alternative Proposal | Proposed a national billionaire tax [1][2][3] |
| Public Opinion on Prop 40 | Divided, with early polling showing slim majority support [4][5] |
Sources (11)
- 1California proposal to tax billionaires makes November ballot | AP Newsapnews.com
- 2It's time for a national billionaires’ tax and a new social compactgavinnewsom.substack.com
- 3California Gov. Gavin Newsom proposes federal billionaire tax and AI "public equity" fund - CBS Newscbsnews.com
- 4California Democrats defy Newsom, back billionaire taxcalmatters.org
- 5Gavin Newsom walks a fine line on taxing the wealthycalmatters.org
- 6California billionaire’s tax qualifies for the Nov. 3 ballot - Ballotpedia Newsnews.ballotpedia.org
- 7Two California tax initiatives targeting personal asset taxes and special tax rules qualify for the ballot in challenge to billionaires’ tax initiative - Ballotpedia Newsnews.ballotpedia.org
- 8Campaign behind California’s wealth tax initiative reports collecting 25% of the required signatures to qualify for 2026 ballot - Ballotpedia Newsnews.ballotpedia.org
- 9California billionaire tax qualifies for November ballotcalmatters.org
- 10California billionaire tax qualifies for November ballot | Sacramento Beesacbee.com
- 11It’s official: California voters will weigh a one-time billionaire taxsfchronicle.com
7. What does the demographic breakdown of the July 2026 Public Policy Institute of California poll reveal about the key voter blocs supporting and opposing Proposition 40?
| Proposition 40 Support | 54% of likely voters (May 2026 PPIC survey) [1] |
|---|---|
| Strongest Support Demographics | Democrats (over 75%), voters under 45, renters, lower-income Californians (May 2026 PPIC survey) [1] |
| Strongest Opposition Demographics | Republicans, white voters, Central Valley residents (May 2026 PPIC survey) [1] |
8. What is the consensus among economic analyses regarding the projected revenue from Proposition 40 versus the potential for capital flight from California post-2026?
| Projected Revenue (Proponents) | Approximately $100 billion over five years (SEIU-UHW, academic researchers) [1][2][3][4][5][6][7][8] |
|---|---|
| Projected Revenue (Opponents) | Approximately $40 billion (Hoover Institution) [3][4][5] |
| Tax Net Worth Date | January 1, 2026 (Proposition 40) [1][2][3][4][5][6][7][8] |
Sources (14)
- 1Proposition 40 [Ballot]lao.ca.gov
- 2Voter guide to Proposition 40: Billionaire taxcalmatters.org
- 3California proposal to tax billionaires makes November ballot | AP Newsapnews.com
- 4Expert Report on Proposition 40, the California 2026...eml.berkeley.edu
- 5California Wealth Taxbusiness.fullerton.edu
- 6California Proposition 40, One-Time Wealth Tax for State-...ballotpedia.org
- 7California billionaire’s tax qualifies for the Nov. 3 ballot - Ballotpedia Newsnews.ballotpedia.org
- 8Two California tax initiatives targeting personal asset taxes and special tax rules qualify for the ballot in challenge to billionaires’ tax initiative - Ballotpedia Newsnews.ballotpedia.org
- 9California Secretary of State Shirley N. Weber, Ph.D., Announces New Measure Eligible for November 2026 General Election Ballot. Imposes one-time tax on certain individuals and trusts. Initiative constitutional amendment and statute.:: California Secretary of Statesos.ca.gov
- 10A.G. File No. 25-0024oag.ca.gov
- 11The Net Present Value of the Billionaire Tax Act: An Assessment of the Fiscal Effects of California's Proposed Wealth Tax | Hoover Institution The Net Present Value of the Billionaire Tax Act: An Assessment of the Fiscal Effects of California's Proposed Wealth Taxhoover.org
- 12Will California’s billionaire tax pay off? New studies clash | Sacramento Beesacbee.com
- 13California’s Wealth Tax Proposal: A Reality Check | Hoover Institution California’s Wealth Tax Proposal: A Reality Checkhoover.org
- 142026 ballot measure polls - Ballotpediaballotpedia.org
9. How might the fundraising and ad spending disparities between the pro- and anti-Proposition 40 campaigns influence voter opinion by November 2026?
| Yes Campaign Funding | Over $31.3 million (as of early August 2026) [1][2][3][4] |
|---|---|
| Opposition Campaign Funding | At least $10.8 million, with over $100 million in collective efforts from business/tech leaders [1][2][3][4] |
| Voter Support | 57% (internal polling for Pro-Prop 40 supporters) [3][4][5] |
Sources (10)
- 1November 2026 General Election | FPPCfppc.ca.gov
- 2Billionaire tax measure wins backing of California Democratic Partysfchronicle.com
- 3New internal poll showing support for billionaire tax - KCRAkcra.com
- 4California labor and Democrats weigh Prop. 40 endorsements | Sacramento Beesacbee.com
- 5California Democrats buck Newsom and union allies by endorsing populist billionaire taxcalmatters.org
- 6California billionaire’s tax qualifies for the November ballot; competing measures pending signature verification - Ballotpedia Newsnews.ballotpedia.org
- 7Two California tax initiatives targeting personal asset taxes and special tax rules qualify for the ballot in challenge to billionaires’ tax initiative - Ballotpedia Newsnews.ballotpedia.org
- 8California billionaire's tax qualifies for the Nov. 3 ballotnews.ballotpedia.org
- 9Voting Outcomes Related to Campaign Spending on California Ballot Propositionsescholarship.org
- 10Is Spending More Potent For or Against a Proposition? Evidence from Ballot Measuresonlinelibrary.wiley.com
10. What Could Change the Odds
Key Catalysts
Key Dates & Catalysts
- Expiration: November 03, 2027
- Closes: November 03, 2027
Sources (14)
- 1California Secretary of State Shirley N. Weber, Ph.D., Announces New Measure Eligible for November 2026 General Election Ballot. Imposes one-time tax on certain individuals and trusts. Initiative constitutional amendment and statute.:: California Secretary of Statesos.ca.gov
- 2California proposal to tax billionaires makes November ballot | AP Newsapnews.com
- 3California Proposition 40, One-Time Wealth Tax for State-...ballotpedia.org
- 4California billionaire's tax qualifies for the Nov. 3 ballotnews.ballotpedia.org
- 5California billionaire's tax qualifies for the November ballotnews.ballotpedia.org
- 6Two California tax initiatives targeting personal asset taxes and special tax rules qualify for the ballot in challenge to billionaires’ tax initiative - Ballotpedia Newsnews.ballotpedia.org
- 7California voters are set to decide on 14 ballot measures this fall - Ballotpedia Newsnews.ballotpedia.org
- 8It’s official: California voters will weigh a one-time billionaire taxsfchronicle.com
- 9California billionaire tax qualifies for November ballot | Sacramento Beesacbee.com
- 10California billionaire tax qualifies for November ballotcalmatters.org
- 11California Billionaire Tax at 19% on Markets Despite 54% Polling Support | Prediction Huntpredictionhunt.com
- 12Prediction Markets Are Skeptical of California's Billionaire Tax - Business Insiderbusinessinsider.com
- 13California billionaire tax: Prediction markets show slide in ballot measure oddscnbc.com
- 14California wealth tax defeats opposing propositions? Pred... 2026 | Polymarketpolymarket.com