The Securities and Exchange Commission chairman Gary Gensler took aim on 9 December at blank-cheque companies known as special-purpose acquisition companies, or Spacs, saying they provide ordinary investors with incomplete information and insufficient protection against conflicts of interest and fraud.

Gensler said he wants to level the playing field between traditional initial public offerings and Spacs, which have exploded in popularity in recent years and now account for more than three-fifths of all US IPOs. The deals typically feature unique incentives that allow backers to multiply their initial investments even if share prices fall and other investors lose money.