From rising interest rates to the prospect of an economic slowdown, tech investors have not been short of reasons for concern in the past year. For now, some of that gloom at least appears to have abated: having lost more than 30 per cent in US dollar terms in 2022, the tech-heavy Nasdaq Composite has posted an astonishing recovery so far this year, posting a gain of more than 17 per cent in the first four months of 2023.