Twitter (NYSE: TWTR) stock plunged 17.8% in trading today (Tuesday) to a new all-time low when its lock-up period expired.
The six-month lock-up prevented insiders from selling approximately 500 million shares of TWTR stock following the company's Nov. 8, 2013, initial public offering (IPO). The first, much smaller chunk of shares (around 9.87 million) exited the lock-up period on Feb. 19, but this had little effect on share price.