Newsom fights billionaire tax ballot as Polymarket prices Shepherd loss at 99%
Gavin Newsom Moves to Block California Billionaire Tax as Polymarket Slams Rebecca Shepherd “Yes” to 0.85%
Reports that California Gov. Gavin Newsom is working to block a proposed billionaire tax from reaching the November ballot before a June 25 deadline have driven sharp repricing in related prediction markets. On Polymarket, traders are positioned heavily against Rebecca Shepherd winning the 2026 Makerfield by-election, with the contract priced as a near-certain "No."
Key Takeaways
- Polymarket prices the "No" outcome at 99.15%, versus 0.85% for "Yes" on whether Rebecca Shepherd wins the 2026 Makerfield by-election.
- The contract shows a steep move lower in the implied chance of a Shepherd win, alongside multi-million-dollar matched volume.
- The market shows a 79.55 percentage-point swing over both 24 hours and seven days in the available history summary.
Chances that a proposed California billionaire tax will appear on the state’s November ballot fell from 88% to 35.5% over the past week on the prediction markets platform Kalshi. The drop followed reports that Gov. Gavin Newsom is trying to prevent the measure from qualifying for the ballot ahead of a June 25 deadline. The proposal, backed by the Service Employees International Union — United Healthcare Workers West, calls for a one-time 5% tax on a billionaire’s net worth and is framed by supporters as a way to bolster the state healthcare system after large federal funding cuts. The union says the tax would apply only to Californians worth more than $1 billion, about 200 people with a combined wealth of $2 trillion, and that it submitted more than 1.5 million signatures, above the 875,000 required. Newsom’s reported opposition comes as he is seriously considering a presidential run, and he said President Donald Trump ordered the Justice Department to investigate him and his wife, which he linked to his potential candidacy.
Polymarket Odds and Flow: “No” at 99.15%, $4.59M Matched Volume, and a 79.55-Point Swing in 24 Hours
Polymarket’s "Will Rebecca Shepherd win the 2026 Makerfield by-election?" contract is priced at Yes 0.85% and No 99.15%, making No the clear leading outcome. Matched volume stands at $4,590,422, indicating heavy participation despite the lopsided pricing. The market data also flags a large swing in the period summary, with change_24h and change_7d both at 79.55 percentage points, underscoring how quickly positioning has shifted.
Watch for further large, single-day changes in the Yes price from the current 0.85% level and whether total matched volume continues to rise materially from $4.59 million.
Beyond the By-Election: California Billionaire Tax Ballot Odds on Kalshi Drop From 88% to 35.5% Ahead of the June 25 Dea
Beyond the local political tape, Polymarket activity is concentrated in bigger cross-border and macro themes, with traders leaning into longer-dated political risk. In “Democratic Presidential Nominee 2028,” Gavin Newsom leads at 24.45% on $1,201,927,171 in volume, while “Brazil Presidential Election” has Luiz Inácio Lula da Silva at 50.5% with $101,158,772 matched. Europe is also drawing attention, with Jordan Bardella at 25.5% in “Next French Presidential Election” on $101,140,561 in volume, alongside more granular contests such as “Peru Election 2nd Round: Margin of Victory? (0.1% brackets),” where “Fujimori 0.2–0.3%” is priced at 89.05%.
Odds Trend
| Window | Change (pp) |
|---|---|
| 24h | +79.5 |
| 7d | +79.5 |
By the Numbers
- Platform: Polymarket
- Market: Will Rebecca Shepherd win the 2026 Makerfield by-election?
- Status: Active (open for trading)
- Leading implied prob.: 0.8%
- Volume: ~$4,590,422
- Top outcomes: Yes: Yes 0.8% / No 99.2%; No: Yes 0.8% / No 99.2%
Related Markets
- Democratic Presidential Nominee 2028 — Gavin Newsom 24%
- Brazil Presidential Election — Luiz Inácio Lula da Silva 50%
- Next French Presidential Election — Jordan Bardella 26%
- Peru Election 2nd Round: Margin of Victory? (0.1% brackets) — Fujimori 0.2–0.3% 89%