recent IPOs in the world of social networking companies, such as Groupon or Linkedin among others. With a valuation close to … its IPO, Zynga showed significant variability, its market capitalization going from 5.6 to 10.2 billion USD, hinting at a … intrinsic value of Zynga. First, we introduce a new model to forecast its user base, based on the individual dynamics of its …

bubble if *S and S deviate from each other. None of these concepts needs any mention of martingales. Our main result then … shows that under a weak absence-of-arbitrage assumption (basically NUPBR), a market has a strong bubble if and only if in … under all possible ELMMs. We show by an example that our bubble concept lies strictly between the existing notions from the …