This map updates itself daily to surface the city-state's newest home resale oddballs. You're looking at units that stuck out like sore thumbs when their sale prices were compared against a regression model (R²=0.90) that controls for location, size, floor, remaining lease, proximity to MRT and hawker centres, and even feng shui factors.
Think of it as a seismograph for the transactions that make you go "alamak!" Methodology here.