High tech companies with most talented employees usually have the most efficiency on their product development. If such a company happens to develop a couple of products or services that play a unique leading role in the market and the market is big enough for it to expand for at least 10 years, then the company can give the stock holder an excellent investment return. It is even better if they can continuously develop new products and market them successfully. Historically there are not a lot of such companies. If you found one in its earlier stage, then you should buy a good amount of the stocks at a fair price and hold for a long time. One of the most important criteria that you need to keep monitoring is the company must be able to keep the most talented employees to do research and development for it. It will need to maintain its absolute leading role in its industry. If they keep losing their most talented employees then it is a signal that it is possible losing its leading role in the industry. If that happens then you should sell the stocks.
Several examples include IBM in early stage of high tech industry, Microsoft in Operating System and Office application software areas, Google in Search Engine area, Facebook in Social Network area, Intel in the Computer Processor industry.
Disclosure: The author has no positions in any stocks mentioned, and no plans to initiate any positions within the next 72 hours.