Shares of Uber Technologies UBER are falling, hitting a new record low after its IPO lock-up period expired on Wednesday. The ride-hailing giant went public in May at $45 per share, but its value has taken a hit since then. UBER stock is down almost 40% since it IPO, and now trades at just under $27 per share.What is an IPO lock-up period?An IPO lock-up period places a restriction on insiders from selling shares of a company’s stock before it went public. The types of insiders include a company’s founders, owners, managers, and employees, and the waiting period typically ranges from 90 to 180 days.Lock-up periods are either required by the underwriters, or imposed by the company that is going public. Investors who want to learn about a company’s lock-up period can find all the information in its S-1 filing with the SEC.IPOs like Pinterest PINS, Snap Inc. SNAP, and Zoom Video ZM all saw their share price impacted by the lock-up period expiration.Just Released: Zacks’ 7 Best Stocks for TodayExperts extracted 7 stocks from the list of 220 Zacks Rank #1 Strong Buys that has beaten the market more than 2X over with a stunning average gain of +24.5% per year.These 7 were selected because of their superior potential for immediate breakout.See these time-sensitive tickers now >>Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report Snap Inc. (SNAP): Free Stock Analysis Report Zoom Video Communications, Inc. (ZM): Free Stock Analysis Report Uber Technologies, Inc. (UBER): Free Stock Analysis Report Pinterest, Inc. (PINS): Free Stock Analysis Report To read this article on Zacks.com click here. Zacks Investment Research