But before you shell out for today's hot issue, take a look at locked shares held by insiders and backers that can't be sold until the lockup expires.
Locked shares can influence an IPO's opening-day pop, and the expiration can trigger a nasty drop.
Saba, which floated less than 10 percent of its shares, doubled in value immediately after the offering. Lexicon, which put more than 20 percent on the block, struggled to maintain its initial price. But the tables could turn when their lockups expire - Saba on October 3, Lexicon the following day. That's because the remaining shares might flood the market as pre-IPO shareholders divest. If that happens, it might take some time for the price to recover.