US stock markets are surfing new highs as better-than-forecast results from technology giants are boosting gains across the sector. Although stronger economic growth in the US and globally has given rise to increased business confidence across the board, it’s estimated that a quarter of the S&P 500’s record-breaking return this year is down to a handful of over-performing tech stars.
The S&P 500’s gains put the index firmly on track to record its 104th month in a bull market. In fact, the price-to-earnings ratio of the US stock market hasn’t been this high since the dotcom bubble of the 1990s. And while there are no signs of an imminent crash, it’s a scenario that’s making some investors nervous.