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I've owned a tech stock that's been hot for a while and I'm getting antsy. How do I determine whether it's as big as everyone else feels it is? - D.S.

Generally speaking, the

technology stocks that can sustain their

momentum longest are those with a difficult-to-unseat proprietary technology that is accepted as a standard within the marketplace. These are the types of companies that have the best chance of sustaining strong

profit margins over the long term, and to which investors will award premium

valuations.

One example would be

Dolby Laboratories

(DLB) - Get Report

, a current pick in the

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newsletter. Dolby is the de facto standard in surround-sound technology, which is included in thousands of consumer electronics products sold each year. Since the marketplace accepts Dolby as a standard, electronics manufacturers have no choice but to use Dolby's technology. This gives me a great deal of confidence that Dolby can sustain its

fundamental momentum over the long term.

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Now when it comes to the tech stock in

your

portfolio, ask yourself the following questions:

1. Is the company's technology accepted as a standard within the marketplace? 2. Are there barriers to entry to getting into the company's market? 3. Is it difficult for customers to switch to a different technology?

If the answer to all of these questions is yes, then your tech company is probably on the right track towards sustaining its momentum over the long term. However, if the answer to one or more of the questions is no, then you will want to be conservative when looking at that particularly stock. For example, a company like

Motorola

(MOT)

makes products that can easily be copied or replaced, so you should have less confidence in the company's ability to generate the type of long-term

growth that commands a premium valuation.

In keeping with TSC's editorial policy, Michael Comeau doesn't own or short individual stocks. He also doesn't invest in hedge funds or other private investment partnerships. Comeau is a research analyst at TheStreet.com. In this role he performs stock analysis for

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, and is also a regular contributor to RealMoney.com. Prior to his arrival at TSC in June 2004, Comeau worked as a Consultant to Toyota Motor North America, performing in-depth research on automotive industry issues, primarily in the areas of alternative engine technologies, competitive analysis and macroeconomics. His primary market interests include consumer technology, specialty retail, and small-caps. Comeau received a bachelor's degree in Finance from Brooklyn College, and has completed Level 1 of the CFA program. He appreciates your feedback;

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