Ballot measure · 3 November 2026

California: Proposition 38 (immunology research bond)

– Probability the measure passes TruthIndex™

Polymarket: 58.0%
Kalshi: 60.5%
Spread: –
24h: –
7 days: –
Updated: Oct 16, 2026, 2:28 PM ET

Yes price, last 60 days

How to read this chart

The green line is the TruthIndex™, the chance of this outcome. It combines the prices on both venues and gives more weight to the venue with more money in its order book. The two thinner lines are Polymarket's and Kalshi's own prices, and the grey band between them shows how far apart the two venues are.

The pale bands behind the lines are the rating zones (Toss-up, Lean, Likely and Safe), so you can see when the race moved from one rating to another. Move along the chart, or use the arrow keys, to read the values for each day.

Prices

Outcome	TruthIndex™		Polymarket	Kalshi	Spread	24h
Yes	–		58.0%	60.5%	–	–

Polymarket Kalshi

Each venue's market

Polymarket$3.2K traded

Prices whether the measure passes.

Yes: Not counted: bid and ask more than 10 pts apart · bid 27.0% / ask 89.0%

Proposition 38 is a California ballot measure currently scheduled for voting on November 3, 2026. It would allow the state to borrow $8.4 billion in debt to research immune system-based technologies for treating conditions including cancer, heart disease and Alzheimer’s. This market will resolve to “Yes” if the specified ballot measure is approved by a majority of voters at the California statewide general election currently scheduled for November 3, 2026. Otherwise, this market will resolve to “No.” If voting on the specified ballot measure does not occur, or the results thereof are not known definitively, by March 31, 2027, this market will resolve to “No”. This market will resolve based on a consensus of credible reporting. If there is ambiguity, this market will resolve solely based on official information from the State of California, including the California Secretary of State (https://www.sos.ca.gov/).

Full rules on Polymarket

Kalshi5.2K contracts traded

Prices whether the measure passes.

Yes: Not counted: bid and ask more than 10 pts apart · bid 39.0% / ask 82.0%

If Proposition 38 passes in California, then the market resolves to Yes.

This market may resolve early once a consensus of designated media sources has declared a winner. See full rules for details.

Full rules on Kalshi