dean evaluation. aswath damodaran will be with us when we come back. you really love, what would you do?" ♪ [ woman ] i'd be a writer. [ man ] i'd be a bakeran ] i wanna be a pilot. [ woman ] i'd be an architect. what if i told you someone could pay you and what if that person were you? ♪ when you think about it, isn't that what retirement should be, paying ourselves to do what we love? ♪ >>> welcome back to the halftime show. it is the most anticipated ipo since facebook and the big question still remains, what is twitter really worth? who better to ask than the dean of valuation himself, professor aswath damodaran of nyu stern joins us from new york. good to see you again, professor. welcome back. >> glad to be here. >> what is twitter worth? let's go right to it. >> i can give you my estimate. my estimate of value is about $10 billion. let me back up and explain why i did what i did. i'm a realist. i know that an ipo is a pricing game, that it's all about mood and momentum and promise and potential and everything is about mult. s and comps. we need to get a sense of the underline reality ands i was trying to start a conversation, pay $1