The stampede of new Silicon Valley unicorns emerging into the world has thinned into a straggling herd.

Venture capital firm Cowboy Ventures recently reported that of 532 US start-ups with billion-dollar-plus valuations in 2023, 60 per cent were what it dubbed “Zirpicorns” — companies last priced between January 2020 and March 2022 when zero-interest rate policies propped up valuations.

Times have changed. Higher interest rates are just one aspect of a more broadly challenging business and market environment that makes private equity firms even more selective about the companies they target for their portfolios.