Yale economist and housing guru Robert Shiller isn’t ready to say the housing market has bottomed.

“There are a lot of positive indicators, but I think people tend to overreact to these,” Shiller tells CNBC. “And if you look at the trend, which has been down since 2006, it’s a pretty strong trend that we have to see reversed. I might call it later this year, that we’ve reached the bottom, but I’m not ready yet.”

Shiller says the big question is whether the housing rebound, which he says has been in large part due to seasonal factors, will continue into the fall and winter. “I believe in momentum in the housing market,” he says. “It looks like upward momentum, but I think it’s too soon to call.”