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: Latin American telecom provider NII Holdings (NAS: NIHD) gained over 20% today on rumors that it would beat analyst estimates when it reports earnings tomorrow.

So what: Jennifer Fritzsche, a Wells Fargo analyst, predicted sales of $1.63 billion and EBTIDA of $310 million in a report today, over the consensus of $1.56 billion in sales and $295 million in EBITDA. EPS estimates stand at just $0.06.

Now what: This prediction seems a little odd coming just a month and a half after Wells Fargo cut its rating on NII from "outperform" to "market perform," and the run-up in the stock adding more than $200 million in market value seems unjustified for what would be just a $15 million improvement in EBITDA. That would equal $0.09 per share if it all went to the bottom line.

The telecom, which operates the Nextel brand in Latin America, has had a forgettable year, dropping more than 80% in the last 12 months as it's badly missed earnings estimates, so investors are clearly hungry for some good news. We'll find out tomorrow morning when the company reports earnings if these gains are deserved, but I say for now it looks overplayed.

Want to stay connected with NII Holdings? Just add it your watchlist by clicking here.