In late trading, Facebook shares were at $21.07, down $1.80 or nearly 8 percent after tumbling as low as $20.36 earlier. Since the Menlo Park, Calif., company went public in May at $38, its shares have traded as low as $17.55.
Barrons, a weekly magazine published by Rupert Murdoch’s News Corp. (Nasdaq: NWS), suggested Facebook faces continued challenges in the advertising space as well as problems from the huge number of options granted to employees which become exercisable over different periods.
Rather than the potential 1.88 billion shares Facebook lists in current filings with the U.S. Securities and Exchange Commission, Barron’s said there are more likely 2.65 billion. As their owners become eligible to receive and sell them, there’s likely to be more pressure on the share price.
As well, the magazine argued Facebook ought to list issuing stock options as an expense like many other technology companies. Not doing so hides potential costs.
Facebook’s price-earnings ratio is a hefty 117, especially because the company reported a big second-quarter loss. By contrast, Apple (Nasdaq: AAPL), the world's most valuable technology company, has a P/E ratio of 16.2 and Google (Nasdaq: GOOG), the No. 1 search engine, has a P/E of 22.2.
“Facebook is valued at $61 billion, or $53 billion excluding its estimated $8 billion in cash.” Barron’s said. “That’s more than 10 times estimated 2012 revenue of $5 billion. Google trades for half that valuation.”
The Facebook fall-off isn’t the first time a critical Barron’s story has affected a stock. On Mondays, the financial weekly’s picks and pans often have great market influence.


![Miss USA 2013: Meet The 51 Contestants Competing In The Beauty Pageant [PHOTOS] Miss USA 2013: Meet The 51 Contestants Competing In The Beauty Pageant [PHOTOS]](http://s1.ibtimes.com/sites/www.ibtimes.com/files/styles/v2_multimedia/public/2013/06/13/miss-usa-contestants_14.jpg)


![Stephen Hester Ousted As Royal Bank Of Scotland (RBS) CEO Following Bank's Talks With UK Treasury [VIDEO] Stephen Hester Ousted As Royal Bank Of Scotland (RBS) CEO Following Bank's Talks With UK Treasury [VIDEO]](http://s1.ibtimes.com/sites/www.ibtimes.com/files/styles/v2_medium/public/2013/06/12/rtr3dngo.jpg)
![Hong Kong House Prices Shoot Up, Greek House Prices Plummet [MAP] Hong Kong House Prices Shoot Up, Greek House Prices Plummet [MAP]](http://s1.ibtimes.com/sites/www.ibtimes.com/files/styles/v2_medium/public/2013/06/11/knight-rank-house-prices.png)


![Turkish Riot Police Enter Taksim Square: Riot Police Clash With Protesters In Attempt To Break Up Protests [PHOTOS] Turkish Riot Police Enter Taksim Square: Riot Police Clash With Protesters In Attempt To Break Up Protests [PHOTOS]](http://s1.ibtimes.com/sites/www.ibtimes.com/files/styles/v2_medium/public/2013/06/11/protester-taking-cover.jpg)
![Flooding In Europe: Floods In Germany, Austria, The Czech Republic, Hungary And Slovakia In Pictures [PHOTOS] Flooding In Europe: Floods In Germany, Austria, The Czech Republic, Hungary And Slovakia In Pictures [PHOTOS]](http://s1.ibtimes.com/sites/www.ibtimes.com/files/styles/v2_medium/public/2013/06/11/flooding-europe-billboard.jpg)
![Robin Thicke Credits Justin Timberlake For Success Of Chart Topping Single 'Blurred Lines' [VIDEO] Robin Thicke Credits Justin Timberlake For Success Of Chart Topping Single 'Blurred Lines' [VIDEO]](http://s1.ibtimes.com/sites/www.ibtimes.com/files/styles/v2_multimedia/public/2011/11/21/193689-singer-robin-thicke-poses-backstage-at-the-2011-american-music-awards-.jpg)






![Fed Chairman Ben Bernanke Press Conference, FOMC Decision: Live Blog [VIDEO] Fed Chairman Ben Bernanke Press Conference, FOMC Decision: Live Blog [VIDEO]](http://s1.ibtimes.com/sites/www.ibtimes.com/files/styles/v2_small/public/2013/06/19/bernanke-news-conference-19june2013.jpg)



![Apple iOS 7: New Features Dazzle At WWDC 2013, Designed To 'Bring Order To Complexity' [PHOTOS] Apple iOS 7: New Features Dazzle At WWDC 2013, Designed To 'Bring Order To Complexity' [PHOTOS]](http://s1.ibtimes.com/sites/www.ibtimes.com/files/styles/v2_small/public/2013/06/10/iphone5-ios-7.jpg)


![Unpaid Intern Lawsuit Against Atlantic Records And Warner Music Group Tests Legality Of Music Industry Internships [EXCLUSIVE] Unpaid Intern Lawsuit Against Atlantic Records And Warner Music Group Tests Legality Of Music Industry Internships [EXCLUSIVE]](http://s1.ibtimes.com/sites/www.ibtimes.com/files/styles/v2_small/public/2013/06/17/wmg.jpg)




Like or Follow us for updates on the biggest stories!