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 Chinese solar-power expert LDK Solar (NYSE: LDK) glittered and gleamed today, jumping as much as 13.2% on about twice their average trading volume.

So what: With no news on LDK, the stock is still beating the rest of the solar sector black and blue here. That's often a sign that large investors are making a move, and the effect is amplified by the fact that about half of LDK's float is sold short. This is a high-beta stock for a reason, people.

Now what: Morgan Stanley (NYSE: MS) and Goldman Sachs (NYSE: GS) would be the most likely big-volume buyers. They are the two largest LDK shareholders outside CEO Xiaofeng Peng, who holds 51% of the company in his own pocket. Both have also increased their stakes in 2011 -- in Goldman's case, tripling its holdings between March and September. Fellow Fool Travis Hoium sees LDK in the lower echelons of the solar industry, but someone out there with deep pockets disagrees today.

Interested in more info about LDK Solar? Add it to My Watchlist.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.