US markets continue to be powered by tech stocks

THE S&P 500 index hit a new high of 3,397.16 points last week, recording its fourth consecutive week of gains. Technology stocks have continued to be big winners, with Apple's market value passing the US$2 trillion mark.

In spite of - or perhaps because of - the Covid-19 pandemic, Apple has sold more devices this year than it expected. Apple is also planning a 4-for-1 stock split, which could attract more investors as each Apple share will be available at a smaller sum.

But concern is also building about the investor exuberance for Apple and other tech stocks. The five largest constituents of the S&P 500 are Apple, Amazon.com, Microsoft, Alphabet and Facebook. Collectively they account for about a quarter of the index's total value. At the same time, the size of these companies has made them targets for regulatory scrutiny.