I am optimistic for what lies ahead in 2012 for the economy and the stock market. While we are indeed in challenging times, a host of great companies are out there doing great things. You just have to know where to find them.

Plenty of low-risk dividend stocks with stable operations and reliable paydays that will do right by investors in the year ahead are still out there.

However, it would be naïve to think it will all be smooth sailing. Lots of stocks are more likely heading for a big fall in 2012, especially as the pressure builds from the eurozone debacle. And as Netflix (NFLX, news) proved earlier in 2011, even Wall Street darlings can crash and burn in spectacular fashion.

Here are five stocks I think are staring at a breakdown in 2012, to sell or even bet against:

1. Cabot Oil & Gas

One lesson investors should learn as they read all the year-end and look-ahead stories is the adage that "past performance does not guarantee future returns." Case in point: A year ago at this time, market darlings included not just Netflix but Crocs (CROX, news) and Green Mountain Coffee Roasters (GMCR, news). Check the performance of those stocks this year, and you'll see that their track records have taken a decided turn for the worse.

So while some may be skeptical about a bearish call on Cabot Oil & Gas (COG, news) after it doubled in 2011, you should review these flops as proof that what goes up can also come down.

Cabot has a nosebleed price/earnings ratio of about 57 based on 2011 numbers, and even if you use the projected $2 earnings per share for fiscal 2012, you're still at a rather pricey P/E ratio of more than 37. Shares have more than doubled in price since mid-2010, while earnings and sales have grown at a modest pace. Other oil-and-gas exploration stocks are also seeing those huge premiums -- Range Resources (RRC, news) has a P/E of almost 42 based on expected earnings, for example -- but you have to wonder if the rush to natural gas stocks is premature.

Critics have raised serious concerns over the environmental impacts of "fracking," a controversial drilling method, after a recent Environmental Protection Agency report linked the practice to water pollution. Regulations could curtail growth for Cabot and others.

2. Chipotle Mexican Grill

I have been leery of Chipotle Mexican Grill (CMG, news) for some time. And while I admit my recent bearish call on Chipotle was a bit premature -- the stock always seems to fight back after a slide -- I see plenty of reasons the stock will be down in 2012.

For starters, Wall Street is littered with the wreckage of hot restaurants that expanded rapidly to deliver big revenue gains and a quick double or triple to shareholders. Krispy Kreme Doughnuts (KKD, news), Cheesecake Factory (CAKE, news), P.F. Chang's China Bistro (PFCB, news) and Ruby Tuesday (RT, news) are just a few of these stories.

Besides, almost every ingredient Chipotle uses is suffering from inflation, squeezing profit margins. And if you've ever been inside a Chipotle, you know that portion control isn't exactly its thing. McDonald's (MCD, news) has burger "manufacturing" down to a science, but Chipotle hasn't figured out portions yet.

Chipotle's growth is indeed impressive. Its five-year growth rate is more than 38%, and the next three years should see annual earnings-per-share growth averaging about 18%, according to Standard & Poor's. But the problem isn't growth, it's expectations. Based on 2012 forecasts of $8.22 in EPS, Chipotle has a ridiculous forward P/E of 39 -- by comparison, the P/E for McDonald's is just 17. Don't think that's a fair comparison? OK, consider fast-growing small-cap Panera Bread (PNRA, news), which has a forward P/E of 24.

Chipotle stock with a P/E of 24 gets you to a little under $200 a share. That's 60% down from here. Ouch.