They recently voted on which of their peers were most likely to succeed, and the top two were both hardware companies, YC founder Paul Graham tweeted yesterday.
Unfortunately, Graham didn't specify which companies they were.
"That's actually fascinating...," serial entrepreneur Jason Calacanis said in response to the tweet. "The hardest things to pull off sometimes have the biggest upside i guess."
Y Combinator is one of the most prestigious and important startup incubators in Silicon Valley. Twice a year, it invests a small amount of money in a hand-picked selection of startups.
But YC's W13 class is much smaller than its last batch. In its Summer class, YC produced more than 80 companies, but decided to limit its Winter class to less than 50 startups.
That's because in Summer 2012, YC grew too fast and "more things than usual broke" when it increased the number of startups from 66 to 84, Graham wrote on the YC blog in December.