Facebook Inc (NASDAQ:FB) earnings were released last week, and although the company beat analyst estimates the market took the news badly, and the company’s shares dropped. The company released a much more detailed 10-K filing on Friday afternoon, and if today’s trading is any indication, more details means more problems for the Menlo Park company.

facebook earnings

The full 10-K filing is available to view on Businessweek.com through this link.

So far today, Facebook Inc (NASDAQ:FB) has lost more than 5% of its value on the market. The company’s shares closed at $31.24 on Friday, but opened at $29.06 on Monday morning. The obvious culprit for the before market drop in the company’s stock is the 10-K filing. The big change between Friday evening and Monday morning was the time allowed to study the document.

But what in the 10-K filing triggered such a bad day for Facebook stock? The major report on the 10-K filing, from Pivotal Research Group, records mainly positive indicators in the company’s business that may have been overlooked in the earnings report. There are certainly several points highlighted by the report that should be positives for Facebook.

Those positives included a widening of the firm’s payments base, moving the firm away from reliance on Zynga Inc (NASDAQ:ZNGA) for social gaming and related revenues. According to the Pivotal report, the 10-K filing indicated more growth in advertising revenue in the United States than the earnings report. Worries after the release of that report included the leveling off of revenues from the United States as mobile usage cannibalized desktop revenue.

There appears to be no real information in the 10-K filing that might lead directly to a substantial fall in the company’s value. Perhaps there is something obscured and noticeable to only the most sophisticated financial analysis, there might be another reason for the fall in the value of Facebook stock.

The fall in value of the company may just be a continuation of last week’s decline. Facebook Inc (NASDAQ:FB) shares rose by a huge margin in anticipation of the earnings report last week, as positive publicity surrounded the company’s new advertising formats and several research firm’s upgraded their ratings and price targets for the company’s stock.

The fall in the company’s stock price today may simply be a reaction to the optimism of the first month of 2013, and the settling of a more realistic valuation on the company’s stock. Facebook Inc (NASDAQ:FB) is expected to grow going forward, but its costs are also expected to increase, stifling any noticeably increasing earnings, even as revenues multiply.

Facebook Inc (NASDAQ:FB) investors are less worried about the stock than they were last May, but many are beginning to reject expectations of massive growth from the company any time soon. Facebook is an amazing firm, with a wide moat and incredible reach. Instead of growing, it appears to want to extend that reach.

If there was any negatives in the company’s 10-K filing, they will surely be made public in some report before the end of this week. Facebook Inc (NASDAQ:FB) may just be suffering from a come down off of the highs of January. Despite the drop in the company’s value, investors don’t seem to be panicking, they simply appear to be readjusting their valuations.