Resolution. Resolves YES if the OBR's October 2026 Economic and fiscal outlook states a margin of £10.0 billion or more against the current budget (stability) rule in the rule's target year, after Budget measures, as printed in the outlook's executive summary. If it reports margins for more than one year, the target year named in the fiscal mandate governs. Resolution Foundation estimated about £5bn before any Budget measures on 7 September 2026.

This market closes at 12:00 UTC on Budget day, before the speech and before the OBR publishes its forecast.

The creator may trade in this market. Resolution follows the sources named above.

If the Budget moves to another date in 2026, this market follows it and the close time moves with it. If no Budget is delivered by 31 December 2026, resolves N/A. Created by Max Ghenis of PolicyEngine (https://www.policyengine.org/uk) as a public record of what PolicyEngine expected before the Budget.

Clarification, 11 October 2026. The margin the OBR states against the current budget rule for 2029-30 governs; if the OBR states only one margin for that rule, that figure governs. If the executive summary prints a whole-billion figure of exactly £10 billion, the one-decimal figure for 2029-30 elsewhere in the same outlook decides. If the Budget amends the current budget rule, the OBR's margin against the rule as amended, in its target year, governs. The outlook as published on GOV.UK on the OBR's behalf counts. The creator holds 51.6 YES shares in this market.