Short-termism is taking on a whole new meaning in the U.S. bond market.

Debt investors can’t get enough of securities with less than 12 months to maturity, thanks to an increasingly uncertain outlook for interest rates and global growth. Exchange-traded funds that invest in ultra-short bonds attracted a record $4.1 billion last week, data compiled by Bloomberg show. Meanwhile, ETFs of one-to-three year notes lost the most cash in a year.

Intensifying worries over weak U.S. data, the impact of President Donald Trump’s multi-front trade war and the outlook for interest rates have whipsawed investors over the last few weeks, fueling demand for haven assets. A portion of the yield curve -- closely watched as an indicator of recession -- is near the most inverted in over a decade, and traders are pricing-in a rate cut by July.

“People are just moving to the sidelines until the economic uncertainties clarify,” said James Solloway, chief market strategist at SEI Investments. “You’re not going to get rich by investing in cash.”

‘Not Strategic’

Investors added more than $3.2 billion to BlackRock Inc.’s iShares Short Treasury Bond ETF last week, the most since the fund began trading in 2007. And State Street Corp.’s SPDR Bloomberg Barclays 1-3 Month T-Bill ETF saw its largest weekly inflow since 2011. Both funds focus on securities with less than 12 months to maturity.

The move to the short-end of the curve is “tactical and short term, not strategic,” said Solloway. Yet government notes that mature in one month currently yield about 2.31%, 30 basis points more than one-year debt.

Ultra-short bond funds may continue to deliver more than short-term funds thanks to the “firmly inverted” yield curve, JPMorgan Chase & Co. strategists led by Alex Roever wrote in a June 7 note.

That’s bad news for slightly longer-term debt funds. The $18.8 billion iShares 1-3 Year Treasury Bond ETF -- previously a beneficiary in uncertain times -- saw its biggest weekly outflow since 2014 last week, with investors yanking $2.1 billion.

With uncertainty set to persist until the Federal Reserve meets next week, it could only get worse.