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 GT Solar International (Nasdaq: SOLR), which sells manufacturing equipment for the solar power industry, raced to a 14% cross-weekend gain today.

So what: Everything started with a fine earnings report after Friday's closing bell, then continued with news of a $203 million private buyback program and the resignation of chairman Brad Forth. If it seems cynical to call the chairman switch an improvement, consider that private equity manager Forth named his own replacement and never intended to run the company for very long.

Now what: The market for solar panels, modules, and films is in flux right now and you never know if it's going to be a good day or a train wreck for the industry as a whole. Evergreen Solar (Nasdaq: ESLR) has provided plenty of examplesof this unpredictabilityrecently, and JA Solar (Nasdaq: JASO) isn't much easierto pin down. But most of them are building out their production facilities and planning for a big future after temporary slowdowns, and that makes GT Solar perhaps the most predictable stock in the solar industrytoday.

Interested in more info on GT Solar? Add it to your watchlist by clicking here.

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 .