NEW YORK ( TheStreet) -- There are always bubbles. There are bubbles in individual stocks, in sectors, in countries, in types of assets and in whole markets.We are forever blowing bubbles because investors have a herd mentality. We follow what works, and it usually keeps working past where it should. The market isn't rational. Whenever prices go beyond reason, the Cassandras come out. I was once one of those Cassandras. Back in the late 1990s, I ran an online newsletter that warned repeatedly about how "clueless" many in the e-commerce space were. I wrote that Internet stocks were in a bubble, and about how it was about to pop. It finally did pop. I think the final straw was the merger of AOL ( AOL) and Time Warner ( TWX) in early 2000. AOL shareholders got 60% of the resulting equity, which in retrospect seems laughable. More important, that deal put an upper limit on what Internet stocks might be worth and, having seen a ceiling, prices went to the floor. But the dot-bomb, as I called it, buried some bargains. In early 2000 Amazon.com ( AMZN) was a bubble stock, peaking during December 1999 at nearly $107 a share. It's now trading for more than $310. Priceline ( PCLN) finished 1999 at a split-adjusted $284.26 after briefly breaching $900 (split-adjusted) earlier that year. Last week it was worth more than $1,050 a share. Am I saying you should buy Amazon and Priceline? No. I'm saying that some stocks can survive a bubble if their management has a long-term vision and the discipline to execute on it. That's the way business, as opposed to investing, works. Thus bubbles, and busts, have little to do with fundamentals for managements that have what I would call A Clue. A wise manager will look beyond the market's horizon, focusing on the long-term plan, and will not deviate. Amazon had a plan for dominating the infrastructure of e-commerce, including the computing infrastructure underlying it. Priceline had a plan for dominating travel. Stocks that are a reasonable investment proposition in the long run can easily create bubbles in the short run. Netflix ( NFLX) was, two years ago, rightly called a bubble by Rocco Pendola. The same was true with Apple ( AAPL)) a year ago. Both have taken their investors on wild rides since, but both are coming good.