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 auctioneer extraordinaire Sotheby's (NYSE: BID) were bid up us much as 16% on fairly heavy trading, with the highest gains coming at the end of the day.

So what: The auction house just announced a string of very successful art sales and surprised investors with a rare gem coming up for auction: the original founding contract for Apple (Nasdaq: AAPL), signed in 1976 by Steve Wozniak, Steve Jobs, and Ronald Wayne. The double-whammy of eye-catching news appears to have unleashed a wave of shorts covering as well, driving the gains ever higher.

Now what: The rather large short cohort has good reason to cash in their chips here, as a monthlong 26% drop is coming to an abrupt end. The covering effect may be magnified even further by robo-trading algorithms, given that 97% of this very volatile stock's float is in the hands of institutional investors. That being said, Sotheby's is nearly 280 years old and has navigated crises like two World Wars, one Civil War, and various great depressions -- the stock looks cheap and nearly risk-free thanks to this piddly little recession.

Interested in more info about Sotheby's? Add it to My Watchlist.

Fool contributor Anders Bylund holds no position in any of the companies mentioned. Motley Fool newsletter services have recommended buying shares of Sotheby's. Try any of our Foolish newsletter services free for 30 days. We Fools don't all hold the same opinion, but we all believe that considering a diverse range of insights makes us better investors. Check out Anders' holdings and bio, or follow him on Twitter and Google+. We have a disclosure policy.