Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of India-based online services seller Sify Technologies (Nasdaq: SIFY) could use some service themselves today, after falling as much as 16.7% on very heavy trading volume.

So what: Sify just reported fourth-quarter results, with a 20% smaller full-year loss compared to 2010, on 2.6% higher sales. It's hard to say whether this was a disappointment; management doesn't play the guidance game, and I can't find evidence of a single analyst following this stock.

Now what: However, the market action speaks volumes, as millions of Sify shares shift to liquidate profits. That's the second massive price plunge in as many days for Sify, though that weakness is more than balanced by the stock doubling in the 30 days before this streak started. As always, you can count on Rediff.com (Nasdaq: REDF) to follow Sify's every jump or crash -- and the other way around. If you're investing in online businesses from India, you'd better stock up on antacids and sleeping pills. Long or short doesn't matter -- these volatile monsters are likely to swing hard both ways.

Interested in more info on Sify Technologies? Add it to your watchlist.

Fool contributor Anders Bylund holds no position in any of the companies discussed here. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool is investors writing for investors.