Facebook Inc.’s market value passed $100 billion amid optimism that the world’s largest social network can bolster sales from mobile advertising.

The stock increased 2.6 percent to $41.60 at 10:48 a.m. in New York, and earlier touched $41.94 for the highest intraday level since Facebook’s debut trading day on May 18, 2012.

The shares had advanced 52 percent this year before Monday, compared with a 17 percent gain in the Standard & Poor’s 500 Index.

The burgeoning market value is a turnabout for Facebook, whose stock slumped as low as $17.73 in September.

Concern about Facebook’s ability to sell more ads for wireless devices weighed on the shares after its $16 billion IPO, the largest technology offering on record. In a sign that Chief Executive Officer Mark Zuckerberg is now making progress in mobile, Facebook last month said ads on smartphones and tablets generated 41 percent of advertising revenue in the second quarter, aided by new promotional tools.

Facebook is now trading at about 181 times earnings. That’s a greater price-to-earnings ratio than all but three companies in the S&P 500, according to data compiled by Bloomberg. A higher multiple can signal that investors think the company may report stronger earnings growth in the future.