(Bloomberg) -- Apple Inc (NASDAQ:AAPL). is about to do something that only two other companies have done since 1990: make up more than 5% of the S&P 500 Index.
Entering Thursday’s trading, the iPhone maker accounted for 4.99% of the index’s weighting. If it passes 5%, Apple (NASDAQ:AAPL) would be the first company to have that much market influence since Exxon Mobil Corp (NYSE:XOM). in March 2009, according to data compiled by Bloomberg.
It’s not the first time Apple (NASDAQ:AAPL) has flirted with the mark. It nearly broke through on Sept. 4, 2012. Back then it topped out at an ever-so-close 4.999% of the index before seeing its stock price plunge by more than 20% to end that year.
If Apple (NASDAQ:AAPL) is able to cross the threshold, it might not be long before it has company. Microsoft Corp (NASDAQ:MSFT).’s weight in the S&P 500 sits at 4.86%. That’s the heaviest the Redmond, Washington-based company has been in the index since the dot-com frenzy at the turn of the century. Microsoft topped the 5% barrier for a single day in December 1999.
The S&P 500 is a capitalization-weighted index that gives larger companies a greater impact on its price moves. Apple (NASDAQ:AAPL) and Microsoft (NASDAQ:MSFT) each now have market values exceeding $1.3 trillion after gaining about 160% over the last three years, compared with the benchmark’s 40% advance.
Combined, the two tech megacaps account for 9.85% of the index, the highest value for any two companies since at least 1990. And lest you think this extreme concentration is just an S&P 500 issue, consider that the two now account for nearly a quarter of the Nasdaq 100 Index and 20% of the entire Nasdaq Composite Index.
