There is a significant divergence between market expectations and mainstream weather forecasts. The highest implied probabilities on Polymarket are for 20°C (32.5%) and 21°C (30%), whereas major weather outlets like The Weather Channel and AccuWeather project a high of 64°F to 67°F (17.7°C to 19.4°C) for London on April 25. This indicates that the market is severely overestimating the likelihood of the temperature reaching 20°C or above.

The rules heavily rely on a single third-party data source (Anera), which carries the risk of data delays or methodology adjustments. Additionally, the market targets the 'second-highest' position and includes an alphabetical tiebreaker, adding complexity and the potential for surprise outcomes.

While tracking the inference revenue of top AI companies is a common industry interest, predicting the 'second-highest' earner for a specific week based on a particular third-party data source is relatively niche and unique.

April 22, 2026 - April 23, 2026: OpenAI's Yes price surged from a low of 20.5c to 79c, while Google's Yes price experienced wild fluctuations (dropping from 76.5c to 14.5c). Simultaneously, all other options like Anthropic and xAI plummeted from around 40c to less than 1c. This was driven by the gradual release of this week's inference revenue data, causing market projections to rapidly converge, confirming that the race is mainly between OpenAI and Google, with OpenAI highly likely to secure the second spot.

This is a market predicting the daily high temperature of a specific city. While weather derivatives exist in professional finance, betting on the exact temperature of a single day is a niche, somewhat novelty-driven topic for general public prediction markets.

The title mentions 'Seoul', but the resolution strictly uses data from 'Incheon Intl Airport Station' (RKSI). Because of the geographical distance between the airport and downtown Seoul, temperatures can differ, which may mislead traders relying on city-center forecasts.

From April 23, 2026 to April 24, 2026, the Yes price for '21°C or higher' surged from 60.5c to 87c, driven by finalized nearer-term weather models confirming a significant warming trend and locking in a high probability for this bracket. In the past 3 days, there had been no extreme price movements exceeding 10c for any single option, as the weather forecasts for this date gradually converged. Trading mostly consisted of micro-adjustments in probability distributions among the adjacent higher temperature brackets (19°C-21°C).

Market prices are heavily concentrated between 29°C and 31°C, whereas the latest mainstream weather forecasts and news reports predict a high of only 27°C or 28°C in Sao Paulo on April 25 due to an approaching cold front. The market has likely not fully priced in this upcoming cooling effect.