Look up IBM (NYSE:IBM) in your favorite news outlet today, and you'd think the company was in deep trouble. Headline after headline focuses on a shareholder lawsuit over IBM keeping its data disclosures to the NSA as secret as possible. Whether the lawsuit has any merit or not, this is hardly good news for IBM and its shareholders. The stock must be suffering today, right?

But when you check up on the damage to IBM's shares, a totally different story emerges. IBM stock is actually up 2.9% in the early afternoon, which is the highest gain of the 30 Dow Jones (DJINDICES:^DJI) components today.

What's going on here? How can IBM actually soar and drive the Dow higher on a day with no positive news to mitigate some significant negative press?

A big clue shows up in IBM's trading volume. IBM shares are on pace for about 8.6 million shares traded today, which would be 75% heavier than an average market day. In other words, someone is buying a lot of IBM shares, and the sheer volume is enough to drive the stock higher.

This makes sense, because IBM started out the morning session within spitting distance of 52-week lows. You can't blame big investors for licking their chops over such an excellent entry point into one of the market's most resilient long-term investments and for putting their money to work at these deep-discount prices.

Who's the big buyer, then? There are three main suspects in my mind:

  • IBM itself. Big Blue is well-known for a tendency to buy back huge chunks of its own stock, often taking out billion-dollar bank loans to finance the buybacks. You can argue all day about the merits and pitfalls of company-sponsored share buybacks, but the fact remains that these big-volume purchases can move markets.

  • Warren Buffett. Berkshire Hathaway (NYSE:BRK-A)(NYSE:BRK-B) famously placed a big bet on Big Blue this year, and IBM is now one of Berkshire's largest direct holdings. Conversely, nobody owns more than Berkshire Hathaway's 6.3% stake in IBM. Buffett is not worried about IBM's growth prospects even as the stock slumps deeper and deeper into Discount City, and the opportunistic investing guru might be tempted to increase his IBM stakes again.

  • Nobody in particular -- i.e., everybody. This boring option hinges on plenty of smaller investors reaching the same value-oriented conclusion about IBM all at once. It only takes a handful of hedge funds and institutional accounts to make a serious difference in IBM's trading volume, and thereby in share prices as well. Perfectly reasonable stuff, but it's always more fun to see a single big hand moving the markets.

We may never really know who moved IBM's share prices today, but there will be clues. Look out for a generous buyback budget in IBM's earnings report next month. Berkshire reports its IBM holdings every quarter in 13F filings with the SEC. That document is due in mid-February and can be skimmed for growing IBM share counts. Absent both of these glaring giveaways, this was just another round of value hunting by a large number of far less interesting players.

Fool contributor Anders Bylund has no position in any stocks mentioned. The Motley Fool recommends Berkshire Hathaway. The Motley Fool owns shares of Berkshire Hathaway and International Business Machines. Try any of our Foolish newsletter services free for 30 days.

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