Appen and Afterpay are at new highs again, the local vanguard of a buying frenzy that drove the Nasdaq to another record overnight, as investors continue to pile into the technology stocks that embody the digital shift from COVID-19.

Tech's stunning rise, with the ASX tech index up 83 per cent since March and the Nasdaq up 48 per cent, has dumbfounded critics who argued a market shock would demolish high valuations, with the combination of falling interest rates and rocketing demand for digital connectivity sending more investors into the sector.