It is still not a happy story with Facebook. After drastically dropping in the first few days of the company’s IPO, they dropped even more.

On Thursday, Facebook shares fell under $20 to a all time low of $19.69; nearly half its IPO at $38. The reason for the drastic drop on Thursday is caused by a lockup agreement with investors. The lockup agreement is a rule set by the Security and Exchange Commission that restrict trading of stocks for a period of time, which is usually 180 days. For Facebook, it is Thursday.  Investors who were eligible to sell today include Microsoft, Goldman Sachs, Elevation Partners, and Greylock Partners.

Even though the lockup agreement has ended, only 14 percent of the 1.91 billion shared will be available in a couple of months.  Not all of the shares are being sold off. Thursday was one of the five stock unlocks over a time period. As of Thursday, an additional 271 million shares are now available to be purchased, increasing the availability by 60%. On October 15, 249 million shares will be on sale; December 14, 49 million more will go on sale; and May 2013, the remaining 47 million shares will go on sale.

With a down-slope like this, Facebook will never hit the $38 IPO. Since Facebook initial public offering, investors have a hard time to know the value of the social network. The company has just barely made analysts estimates. Facebook will hit some turbulence in the months coming ahead, as more and more stocks are unlocked; though investors are in it for the long run.