This market resolves YES if Russia officially rejoins the G7 (making it the G8 again) before January 1st, 2026. Resolution will be based on official partecipation of a russian representative at a G7/G8 summit.
The number of nations in the group is not substantial to this market, if the number of nations in the group after Russia joins is not 8 (for example because some other country leaves, or joins) the market still resolves yes as long as Russia is part of the group.
Update 2025-02-20 (PST) (AI summary of creator comment): Important Update:
If a scenario arises where most current members of the G7 have left and the remaining members form a new group (e.g. a G2),
Even if Russia joins this newly formed grouping, it will be treated as a new group rather than Russia rejoining the G7/G8,
In such a case, the market will resolve as NO.