As of Tuesday's close, many star technology stocks, including Facebook, netflix and amazon, have hit record highs.

Facebook shares continued to rise after data leakage concerns faded and at one point hit a new high of $202. That puts CEO mark zuckerberg worth $81.6 billion. That means the wealth gap between Mr Zuckerberg and Mr Buffett has narrowed to $29m.

Netflix shares rose to $416.7 and are up more than 111% so far this year,which is the second highest in the s&p 500. In addition, since its market value surpassed that of Disney on May 24, netflix has been the no.1 player in the global media industry. In addition, amazon shares have risen to $1,750.

Since early June, the nasdaq composite index has hit back-to-back closing highs as several leading technology stocks, including Facebook, amazon, netflix and Google parent Alphabet, have risen. In addition to the high-profile FANG, another group of tech stocks has been quietly moving higher in recent months: the s&p software and service selection industry index is now at an all-time high.

The index is up more than 23 percent so far this year, which also helped propel the nasdaq composite higher. According to a recent report by fidelity investments, Software stocks were among the biggest beneficiaries of the tax cuts introduced by the trump administration late last year, with shares of cloud communications firm Twilio and procurement Software supplier Coupa Software all rising more than 100 percent this year.

Technology stocks are even more dominant in the u.s., with a combined value of more than $6.6 trillion, according to bank of America merrill lynch. But the sheer size of tech stocks has also raised concerns about whether investors are too optimistic about the future profitability of tech companies. For much of the past year, betting on tech stocks has been the most crowded trade, according to bofa merrill lynch's monthly survey.

There are concerns about technology stocks, but the call to remain bullish on tech seems even louder. Hedge fund legend and current tiger founder Julian Robertson also weighed in on tech, saying valuations are low and there is no bubble in tech stocks relative to growth prospects. Of the 199 analysts who track FAAMG, only five have a 'sell' rating, according to bloomberg data. No analysts have a "sell" rating on apple or Google parent Alphabet.

At the moment, almost all of the highest value companies on the US stock market are tech companies. A decade ago, it wasn't them. It was exxonmobil (oil), general motors (manufacturing), Microsoft (software), citigroup (finance), bank of America (finance). During this decade, the IT industry and Internet business in the United States have been developing rapidly. In a short period of ten years, these companies have overturned the century-old road of traditional industries and indicated the future development direction of the American economy.