Shares in bitcoin-hoarding companies have tumbled in recent weeks as investors grow increasingly concerned about an overcrowded market, in the first major setback for the “crypto treasury” craze that has swept financial markets this summer.

Strategy, the world’s biggest corporate bitcoin holder, has fallen 18 per cent over the past month to its lowest level since April, dragging down shares in a slew of groups that have aped founder Michael Saylor’s use of a public company to stockpile cryptocurrencies.

Companies across the world this summer rushed to raise debt and equity to buy bitcoin and other tokens such as ether, solana and XRP in an effort to boost their company valuations, enthused by US government support for the crypto industry. Led by Strategy, many groups’ share prices soared to well above the value of the tokens they held, in a sign of investors’ belief in this business model.