Following the U.S. stock market crash of March, Amazon (NASDAQ:AMZN), Alphabet (NASDAQ:GOOGL), Facebook (NASDAQ:FB), Apple (NASDAQ:MSFT) and Microsoft (NASDAQ:MSFT) combined have added $2.7 trillion to their market cap.

Meanwhile, the stock markets disconnect with the real economy has gotten worse.

While U.S. GDP has lost $2 trillion, the stock market has added $4 trillion to the total market cap of companies in the S&P 500.

Of course, the Federal Reserves balance sheet explosion has aided the stock market rally since March.

The Feds balance sheet expansion has been a common factor in the tech giants rallies since March. These tech companies, along with Tesla (NASDAQ:TSLA), have carried the stock market higher over the past four months.

As the economy suffered under government lockdown orders, the big tech giants were in prime position to smash earnings expectations in Q2.

Apple shares rallied more than 10% to make new all-time highs after reporting sales growth of 11% in Q2 2020 results. Last weeks rally allowed Apple to overtake Saudi Aramco as the worlds most valuable company.

Amazons second-quarter saw the companys sales take off despite the coronavirus pandemic-induced slowdown. Its shares rallied post-earnings before undergoing a bit of profit booking.

Meanwhile, Facebook reported revenue growth of 11% despite an ad boycott from various companies. Its shares gapped up almost 7% post-earnings before a mild selloff.

Alphabet rallied 38% from the March low. After reporting an unprecedented revenue decline, its shares declined post-earnings.

High expectations from Microsoft made the stock rally 25% from the March lows. After reporting spectacular earnings, the stock continued its uptrend.

While Facebook, Amazon, Alphabet, Microsoft, and Apple have returned 35% in 2020, the remaining 495 stocks in the S&P 500 are in the red.

These giants have carried the stock market on their shoulders; if any one of them drops abruptly, the whole market could enter a downward spiral.

Because of this, analysts at Morgan Stanley have predicted a 10% selloff in the U.S. stock market.

If the prediction comes true, the selloff would be reminiscent ofwhat happened to the Nifty-Fifty stocks back in the 1970s. Nifty-Fifty refers to the group of 50 stocks that led the markets toall-time highs in the early 1970s, followed by a 46% crash.

While these stocks had led the rallies to the top, they also led the nosedive that followed.

Back then, Forbes wrote,

The Nifty-Fifty were taken out and shot one by one.

Could the same happen to the tech giants driving the market rally in 2020?

Disclaimer: This article represents the authors opinion and should not be considered investment or trading advice from CCN.com. Unless otherwise noted, the author holds no investment position in the above-mentioned securities.

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Nifty-Fifty All Over Again? Why Investors Should Fear Big Tech Rally - CCN.com