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 oil explorer BPZ Resources (NYSE: BPZ) didn't just pop; they exploded as much as 29% higher in intraday trading on heavy volume today.

So what: The company announced estimates for Block Z-1 in Peru and its intent to identify a partner for the area. A report from the company's independent reserve auditor -- Netherland, Sewell and Associates -- estimates there's 981 million barrels (MMBO) of unrisked prospective oil in Block Z-1, with low and high estimates of 269 MMBO and 2,750 MMBO, respectively.

Now what: A short squeeze is adding fuel to the move today because 17% of the float was short as of the end of May. Today's move is a welcome sight for investors who had recently seen shares hit a new 52-week low and get pounded by short-sellers. I think this move has more legs in the short term considering the short-sellers who have to start getting out now.

Interested in more info on BPZ Resources? Add it to your watchlist.