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 Internet service vendor Sify Technologies (Nasdaq: SIFY) soared last week but are coming back to earth today: the stock got as much as 15% cheaper today amid heavy trading.

So what: Once again, Sify has no news to drive the trading action. Fellow India-focused online services provider Rediff.com (Nasdaq: REDF) is also flagging today for no particular reason.

Now what: Sify does report earnings in the early morning hours tomorrow, so you're watching the market adjusting ahead of that event. Given that the stock has more than tripled year-to-date and that a staggering 20% of its float was sold short at the latest reckoning, some caution is probably prudent. Call it a shakeout of nervous traders or sated investors taking some profits, but the result is the same: Sify is sinking today, and whether the company meets or misses estimates in tomorrow's report, the ensuing market action should be explosive.

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.