Source: Wayfair.

What: Shares of online home furnishings retailer Wayfair (W -0.02%) rose as much as 10.9% in Monday's trading, all on no particular news and below-average trading volume. By 3:30 p.m., the stock had settled and was up 5% from the previous close.

So what: The only serious news item on Wayfair's table today comes from Pinterest, which just added support for the store to its "Buy" button. The privately held social network launched this instant e-tailing solution earlier this summer, and hopes to build a significant revenue stream on it.

Now what: Pinterest's Buy button has boosted stocks before, but Wayfair is much larger and more established than these earlier jumpers. The lack of heavy trading volume also undermines the Pinterest theory, since a significant business move would spark big volumes alongside the rising share prices.

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.

In short, you can chalk this move up to just another day in the life of a volatile stock under uncertain market conditions. The three major stock indices rose more than 1.5% on Monday, bringing all kinds of volatile tickers along for the ride.

Wayfair has only been publicly traded for a year, and investors are still feeling this unfamiliar business out. Some 73% of the stock's float is currently sold short, which does absolutely nothing to calm the waters around this ticker. Expect the rough waters to continue for quite a while, including sudden and largely inexplicable moves both to the upside and the downside.