**High advance voting and strong early participation on referendum day have positioned 80–85% turnout as the leading outcome in this market.** Record advance ballots—exceeding 63,000 or roughly 23% of the electorate—combined with midday figures showing Reykjavík turnout already surpassing 2024 parliamentary election levels signaled elevated engagement driven by the close contest over resuming EU accession talks. Rural and urban districts both reported robust participation, with the national broadcaster noting rates climbing toward or above the prior election’s 80% benchmark. The polarizing debate on fisheries sovereignty, currency stability, and Iceland’s relationship with the EU heightened voter mobilization without the dilution typical of lower-salience votes. Traders’ implied probabilities reflect these pre- and early-vote indicators, with 80–85% capturing the consensus range around the observed 82.5% final figure while lower and higher brackets account for residual uncertainty in final tallies.