I have never spent much time on momentum stocks. These stocks tend to move higher and higher with seemingly no regard for the fundamentals of the underlying business. When momentum investors lose interest and sell their stakes, there's little support in place, and these stocks can tumble swiftly lower.

Just in 2011, we've seen some of the most popular momentum stocks get crushed in a very short time. Restaurant reservations firm OpenTable (Nasdaq: OPEN) soared from $ 70 at the start of the year to above $ 170 by late April. But once signs of a slowdown emerged, the stock fell and fell until bottoming out around $ 30. Netflix (Nasdaq: NFLX) has quickly morphed from the company that could do no wrong into the company that could do no right, and now trades for about one-fifth of its 52-week high.

At some point, these beaten down stocks could represent real value, and intrepid investors can start to wade in. The key is to wait until all of the sellers are flushed out. This approach is especially crucial at a time known as the "December effect." Historically, any stock that has fallen sharply is a candidate for even more selling at the end of the year as investors seek to dump losers to offset their winners for capital gains tax purposes. This action is now so widely anticipated that these stocks now get sold off a month ahead of the anticipated traditional tax-loss selling period. So some of these big losers can actually start to rebound in late November and pick up a head of steam in December and beyond.

That's what I think is happening with Sodastream (Nasdaq: SODA), which makes a carbonated drink machine for individual home use. (If you're familiar with Green Mountain Coffee's (Nasdaq: GMCR) Keurig device for coffee, then you can begin to see parallels between the two stocks, in more ways than one.)

Simply put, I think the stock is slowly springing back to life after a precipitous fall.