Definition of “eruption” – An event counts if the Smithsonian Global Volcanism Program (GVP) or the Italian Istituto Nazionale di Geofisica e Vulcanologia (INGV, Osservatorio Vesuviano) explicitly logs it as an eruption that produces juvenile magma at the surface and assigns (or is later assigned) a Volcanic Explosivity Index (VEI) of 2 or higher.
Rationale: VEI 0–1 phreatic blasts and vigorous fumarolic bursts are common at Campi Flegrei; we want to exclude those.

Time window – The eruption must start between 00:00 UTC on 8 July 2025 and 23:59 UTC on 31 December 2025.
If activity begins inside the window and continues past 2025, the market resolves YES.

Sources & adjudication –

• Primary: official daily/weekly bulletins from INGV – Osservatorio Vesuviano or the GVP Weekly Volcanic Activity Report. volcano.si.eduingv.it

• Secondary (for redundancy only): peer-reviewed papers or major wire services quoting those agencies.

Edge cases –

• NO for seismic swarms, uplift (bradyseism), degassing, or hydrothermal/phreatic explosions without new magma.

• NO if GVP/INGV later downgrade the event below VEI 2.

• YES even if the VEI is uncertain at first but later confirmed ≥ 2 by either agency.