We examine theories of IPO underpricing using unique data from Israel where the allocation to subscribers is by equal proration. This enables us to simulate the return earned by uninformed investors. Consistent with Rock's (1986) theory of adverse selection, allocations were negatively related to underpricing. But uninformed investors earned a negative allocation-weighted initial return, although the average initial return was 12%. They could break even, however, by using publicly available information. The data also supports Welch's (1992) theory of information cascades: demand is either extremely high or there is undersubscription, with very few cases in between.

We study the effect of trading consolidation by examining the response of liquidity and stock price to the exercise of deep in-the-money corporate warrants. This enables a relatively clean test of the value of trading consolidation. The exercise at the warrant expiration is fully anticipated and has no information content. An effect can come from the value of trading consolidation that improves liquidity. Indeed, we find that liquidity and stock prices both increase significantly at warrant expiration. Further, the price increase is positively related to the pre-exercise extent of fragmentation, to post-exercise improvement in stock liquidity, and to the proportional increase in the number of shares following the warrant exercise.