As I follow what I perceive to be an expensive U.S. stock market, I find myself drawn to examples of over-valued stocks. Here are 14 stocks I wouldn’t even think about owning at their current prices and price to earnings ratios:

data from www.marketwatch.com

A few comments:

1. The stocks listed above are ordered by P/E ratio, but if I were listing them in terms of investment potential, I’d probably list Google, Apple, and maybe Mastercard at the top and Amazon, Bankrate, and Priceline at the bottom.

2. Did I miss something with Amazon’s stock lately? The company releases a single good earnings report and the stock takes off like a rocket ship. Welcome to 1999 but 8 years later. Amazon has been around for too long not to be making greater profits. Unfortunately, this company will never live up to the expectations required to justify a P/E ratio of over 100.

3. And Priceline? Sure, the stock costs less than it’s Nasdaq-bubble peak of $1,000 a share, but it’s still 47 times earnings, with the stock price doubling in the past year. Does anybody really think this company is a long-term winner?

4. Who cares about P/E ratios? I certainly do. In my view, a P/E ratio higher than 30 can only be justified by a small minority of companies for whom future earnings are likely to greatly exceed current earnings. While it’s true that some of the companies above may fit this description ex-post, the majority of them have future earnings paths too unpredictable to justify such an extreme P/E.

Earnings ratios may not matter for short-term market trends, but when the music stops you’d better be holding stocks that are backed up by real profits. If not, there’s no telling how much prices can fall.

5. I’m still not a buyer of Google, even though I think it’s a great company. Even if Google earns spectacular earnings growth for the next 5 years, the company stock price still won’t be justified in my mind. Call me when the P/E ratio is down below 20.

6. I commented on possibly shorting RIMM in March when it was trading at $135. The price has since risen 20% in three months. Does that mean I was wrong to think the stock price was too high? Maybe, maybe not. The timing of these things is very difficult. But I do know that unless this company’s earnings shoot to the moon, the price will come back to earth eventually.