FYI: Before bond exchange-traded funds launched in 2002, accessing the fixed-income market wasn’t always easy. Investors could own individual bonds—but because of the size and cost, institutions mostly bought them. Smaller investors could buy actively traded mutual funds and pay higher fees and not be sure of the holdings
Regards,
Ted
https://www.etf.com/publications/etfr/how-bond-etfs-changed-investing?nopaging=1