Why are investors still bullish on highly valued tech stocks?

The Big Tech rally of this year has further to run as the risk of a US recession drives investors into stocks that offer profitable growth in lean times, according to the latest Markets Live Pulse survey.

Some 41% of 492 market participants surveyed said the highest returns this year would come from buying quality stocks focused on profitability, while selling those that disappoint on those factors. That includes taking long positions in companies like Apple Inc. and Microsoft Corp.,...