Power traders are fueling a boom in weather data, which helps them to anticipate sudden price swings. Weather forecasters are finding a lucrative niche in Japan's power-trading boom, selling hyper-specialized data to firms seeking an edge in one of the world's most volatile electricity markets. Weathernews is among a handful of companies cashing in on demand for meteorological data. The Tokyo-listed company's shares have surged 50% in the last year as investors bet on its expanded use of artificial intelligence, among other factors. The firm says it's supplying -- or is in talks to provide -- data to several dozen power traders, about a third of which are based outside Japan.