I did a search on Kayak for an upcoming flight and it's price trend suggests waiting, citing 60% confidence that the price of the ticket will do down. However when I search for the exact same flight on Bing Travel it suggests buying the ticket, citing 80% confidence that the price of the ticket will go up. The real stumper is that Bing's results are powered by Kayak.
Does each site use a different algorithim to determine the price trend? Does anyone have any advice on which is more accurate?