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
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 $10,000 order loses about 7% of the price to slippage.
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