Picking the Lockup Knot

Lockup expiration, the first time after an IPO when insiders can sell stock, has become an important stock-trading tool. But figuring out when lockups expire is no simple task.

Several online sites carry information about lockup expirations, but none is a foolproof guide. EDGAR Online and IPOLockup.com publish charts that list IPOs and 180-day lockup expirations. But they don't include the number of shares that could hit the market, nor do they include 90-day lockups. Some companies also stagger the release of shares, unlocking a number of shares after a quarterly report or other event. So, in many cases, figuring out lockups requires a closer look.

Investors may want to pore over Securities and Exchange Commission filings. It's time-consuming, but so far is the only way to get comprehensive information. Here's how it's done. ...