Largest Company prediction markets

This room reads Polymarket's markets on the world's largest companies by market capitalisation. The lead market asks which company is the largest at market close on the last day of the month; a year-end version runs beside it, with separate markets for second and third place and for the most valuable private companies.

Market capitalisation is the share price times the shares outstanding, so the ranking changes with every trading session, and two companies a few percent apart can swap places on one earnings report. The monthly markets settle on the ranking at that month's market close, on a consensus of credible reporting.

A price is the cost of a contract that pays $1 if the outcome happens, so 62¢ reads as a 62% chance. In a market with many named outcomes the prices should add up to roughly 100%; a gap is the venue's spread and fees, not a free lunch.

Each market resolves on its own written rules, including the deadline, the resolution source and what counts as the event. Two markets on the same subject with different wording can and do trade at different prices, so read the rules on the market page before comparing them.