I've been looking around at some stock ideas for the Prosocial Portfolio I manage for Fool.com. I have a watchlist of possibilities. I was hoping to find some sleepers that seem to be trading at relative bargains, and I'm running into disappointment. And you know what? I'm getting even better proof to support my sense of just how bubbly so many stocks have become.

Some of these skyrocketing stocks are even already in the portfolio. Given my long-term view, I won't sell on panic about the idea that they may be considered "overvalued" -- unless I get the sense that the business thesis has materially changed for the worse. Obviously, given the portfolio's parameters, these are stocks I purchased because of their companies' sense of ethics, innovation, great management, and good business, which make them worth the ultimate ups and downs of short term "bear markets" and "bull markets."

We may go on a roller coaster when the market (finally) corrects, and that day will come. Those of us who are long-term investors will have to ride it out as long as we have great companies in our portfolios.

No bargain on this bunny right now
The Prosocial Portfolio includes stocks that take socially responsible (or just plain responsible business) factors into account. These are intended to be long-term holdings, exhibiting great growth potential for the future due to positive attributes and innovative visions.

In looking for some possible additions from my watchlist, so many stand out as stocks that I'd rather buy on temporary weakness rather than purchasing now. This reflects the market's "irrational exuberance," the Alan Greenspan phrase alluding to the possibility of dot-com craziness back in the day.

Annie's (NYSE: BNNY) is one I wish I could bring myself to buy. However, a quick glance shows a forward price-to-earnings ratio of 38. Its PEG ratio, which takes five-year growth prognostications into account and can be a useful rule of thumb, is 2.0. Now, at times I'll certainly ignore such ratios because I believe that analysts and investors have got the growth potential wrong.

However, Annie's has a lot to prove going forward. The consumer goods company is best known for its organic macaroni and cheese. It's expanding into various other areas -- it absolutely has to. Mac and cheese is delicious, but the market is limited. Annie's must convince consumers to embrace many new branded products such as pizzas, salad dressings, and frozen meals.

Annie's most recent quarterly results disappointed investors. Quarterly net income was just about flat, although sales increased 13.8%. Snack foods took the lead in increasing sales; although meals, dressings, and condiments still showed growth, both declined as a percentage of sales.

On a brighter note, Annie's management reported an enthusiastic response to its microwavable macaroni-and-cheese cups from retailers, and it's debuting family-size frozen meals. Still, there's uncertainty as to how much traction Annie's can make in other areas.

Facing the growing gluten challenge
One of the stocks that I have bought twice for the Prosocial Portfolio, Hain Celestial (HAIN -0.42%), offers brands that are already well-known on grocers' shelves. These include Celestial Seasonings, Arrowhead Mills, Rice Dream and Soy Dream, Garden of Eatin', Terra Chips, Ethnic Gourmet, and many more.

Hain Celestial's stock price has also been on a major upward trajectory this year, but its valuation is lower than Annie's. Its forward P/E is 23, and its PEG ratio is a slightly lower 1.77. When I bought more shares on temporary weakness in December 2012, the stock was trading at 19 times forward earnings and a PEG ratio of 1.36.

Boulder Brands (BDBD.DL) is an interesting stock idea recently mentioned by a longtime Foolish community member on the Prosocial Portfolio discussion board. The company's focus on products for folks with dietary restrictions, such as plant-based Smart Balance and gluten-free options like Glutino and Gluten-Free Pantry, certainly lend it the possibility of major growth.

More and more Americans are finding themselves eating gluten-free diets out of necessity, and Earth Balance is for those who choose plant-based diets. (Meanwhile, Smart Balance is also useful for those who are trying to control cholesterol levels.)

Earlier this year, Food Business News reported that the market for gluten-free products will reach $6.2 billion by 2018, catapulted by increased celiac disease and allergies, as well as the general desire to eat healthily. Earlier this year, NPD reported that 30% of adults are decreasing their gluten intake or giving it up entirely.

Still, Boulder Brands is trading at 35 times forward earnings and sports a PEG ratio of 3.00. I find those figures daunting. While I don't adhere solely to stock prices and traditional ratios for my theses -- I've purchased Costco for the Prosocial Portfolio at times when many investors might have called the price insane -- I have to get a good feeling on other factors such as whether the market is larger than most can imagine and whether the management is great as well.

Waiting for the running of the bulls to pass
Boulder Brands and the growing market for gluten-free items does strike me as a compelling stock idea right now, while I still want to leave Annie's alone. In some cases, the growing market Boulder Brands addresses goes beyond changes in consumers' choices -- they're related to real health ramifications. I have a funny feeling many of us know at least one person with celiac disease or an allergy to gluten. Obviously, there seems to be a true growth story there.

Still, I'm holding off for a bit and keeping an eye out for temporary weakness. If I change my mind I'll buy it for the Prosocial Portfolio, but for now, I'm still waiting for a lower price to present itself. Sometimes good things come to those who wait -- and good values, too.

Unfortunately, in a raging bull market, long-term investors' waiting game is even harder.