Facebook shares have lost nearly half their value since a highly-touted public offering in May, but it’s still not a bargain for some.

Facebook in the past week dropped below $20 a share for the first time since its $38 offering price in May. On Friday, the stock rebounded five percent to $21.09 but remains down a hefty 44.5 percent.

There is some fear that shares could take another hit in mid-August after the expiration of a “lockup,” a 90-day period after the IPO during which insiders are barred from selling.

Michael Comeau of the financial website Minyanville says 268 million shares could come onto the market, in addition to the 460 million that are already floated. And more will become available later this year.