Facebook joins the $100 billion club

Getty Images

Facebook CEO Mark Zuckerberg

"A million dollars isn't cool. You know what's cool? A billion dollars," Justin Timberlake's Sean Parker memorably remarked in "The Social Network," the 2010 movie about Facebook.

That must make $100 billion downright awesome.

Shares of Facebook rose by a dollar as of Monday afternoon, meaning that the company is now valued at over $100 billion for the first time since its IPO. The stock has risen nearly 60 percent since July 24, when Facebook reported very strong earnings that showed a 61 percent increase in advertising revenue.

(Read more: Facebook stock cracks $40—now what?)

Facebook is now worth more than McDonald's, Conoco Phillips, American Express or Goldman Sachs. But unlike those companies, Facebook is being priced on its future potential much more than on its near-term stream of earnings—as a glance at projected net profits tells us.

Analysts expect American Express to earn $5.3 billion in 2013, McDonald's to earn $5.6 billion, Conoco Phillips $7.1 billion, and Goldman $7.9 billion. Meanwhile, Facebook is expected to earn $1.7 billion— about a fifth of Goldman's projected earnings, despite being worth $28 billion more than the financial giant.

For CNBC contributor Brian Stutland of Stutland Volatility Group, this indicates that "investors way willing to pay up for the stock now and then wait for it to grow into its valuation."

This focus on the future puts a great deal of pressure on the company's third quarter earnings, which will be released in late October.

(Read more: No more 'real' gifts on Facebook—It's cards from now on)

"To me, the only thing I'm really focused on is their ability to put up two consecutive quarter showing the growth they did in mobile adds," said Dan Nathan of RiskReversal.com. "And the closer we get to third quarter results and the higher the stock goes, the harder it's going to be for them to beat expectations."

Nathan says this could be especially difficult in light of a remark that Facebook CFO David Ebersman made on the Q2 conference call. "We expect newsfeed ads to remain the river of revenue graph in the second half of the year," Ebersman said. "However, remember that newsfeed ads really began to contribute to our revenue in the third and fourth quarters last year, which will make for more difficult year-over-year comparisons in Q3 and Q4 relative to Q2."

This more difficult comparison could mean that Facebook shows much lower ad growth in the third quarter than in the second. "That's something that traders and investors are going to keep their eye on," Nathan said.

On the upside, Nathan thinks that the fact that shares have traversed the memorable $38 IPO price could be great news for shareholders.

"Many, including myself, thought $38 would be psychological resistance, and now it could be support," said Nathan, who is a CNBC "Options Action" contributor.

Some see the shares rising above $50 this year. In the options market, the January 2014 50-strike calls were very popular, with many people buying them in order to bet that Facebook will rise above $51.40 by January expiration.

And if Facebook does rise to $51.40? Well, then the company would then be worth more than Home Depot, Intel, Disney, or Visa.

Now that would be cool.

—By CNBC's Alex Rosenberg. Follow him on Twitter: @CNBCAlex.

Follow the show on Twitter: @CNBCOptions.