The return of Fomo – fear of missing out – is fuelling concern that the market may take a tumble. 

Strong earnings and an overall downward trend in inflation have helped fuel a surge in the S&P 500 that few would want to miss. But with much of the index’s 30 per cent rise over the past 52 weeks stemming from just a handful of stocks, such as artificial intelligence play Nvidia Corp, some market watchers fear there may be a melt-up unfolding.