THE SPecial-purpose acquisition company (SPAC) was Wall Street’s favourite get-richer-quicker scheme during the pandemic. First, some big-shot investor raises capital by listing a shell company on the stockmarket. The big shot then calls around other big shots, looking for a moonshot. When a captivating private company is found, it merges with the shell, whose investors choose to redeem their shares or own part of the resulting business. SPACs can be a wheeze for those who set them up (in return for a cut) and the investment bankers who advise them, but have tended to be less good for investors who pay these costs.