Trader consensus on the "Is Earth flat?" market rests on overwhelming scientific evidence from satellite imagery, orbital mechanics, and centuries of navigational data confirming a spherical planet. This 99.3% implied probability for "No" reflects the complete lack of credible challenges in recent years, with flat-Earth assertions limited to fringe online spaces that have produced no verifiable data or breakthroughs. Ongoing space missions and geophysical monitoring continue to reinforce the established model, aligning with historical precedents in astronomy and physics. Realistic upset scenarios would demand a global conspiracy or paradigm-shifting discovery contradicting all known evidence, developments that remain extraordinarily unlikely given persistent empirical scrutiny.