The rise of exchange-traded bond funds is both rapid and relentless.
To get a sense of the momentum, take a look at LQD. The iShares iBoxx Investment-Grade Corporate Bond ETF, or LQD, as it's also known, is the world's second-largest bond ETF and it took in $1.1 billion of new funds on Thursday. That's its biggest daily inflow ever and the largest ever recorded for a corporate bond ETF, according to data compiled by Bloomberg.
LQD invests in high-grade dollar bonds from corporations, including Anheuser-Busch InBev NV and Verizon Communications Inc. Its largest daily inflow before Thursday was $628.9 million in May 2013.
Global fixed-income ETFs, which track bond indexes and trade like stocks, attracted $66.7 billion of inflows this year, according to data compiled by BlackRock Inc. That puts the market on pace to top last year's record total of $91.7 billion.