The amount of money in fixed income exchange-traded funds passed $1tn last month, an ascendance that has reshaped the market in which countries and companies raise money to pay their bills.

Just 20 years ago, bond ETFs did not even exist. The bond market was a largely sleepy enterprise that had long resisted the high-tech upheaval that transformed the way stocks are bought and sold. Even today, the biggest bond trades can take hours, or even days, while billions of dollars in stocks change hands in seconds.