Sam Altman, the head of Silicon Valley startup accelerator program Y Combinator, doesn't think the tech industry is in a valuation bubble.
But he does think startups are burning "frightening" amounts of money every month.
Altman detailed his fears in an email he sent to Y Combinator alumni this past weekend, and in a phone conversation with Business Insider on Monday morning.
Image: http://www.businessinsider.com
