UC Irvine

We explore how information ambiguity and traders’ attitudes toward such ambiguity affect expectations and asset prices under three different market institutions. Specifically, we test a theoretical prediction that information ambiguity will lead market prices to overreact to bad news and underreact to good news. We find that such an asymmetric reaction exists and is strongest in individual prediction markets. It occurs to a lesser extent in single price call markets. It is weakest of all in double auction markets, in which buyers’ asymmetric reaction to good/bad news is cancelled out by the opposite asymmetric reaction of sellers.