NEW YORK (Bloomberg) — Treasury benchmark 10-year notes posted their biggest weekly gains in five months as investors sought the safety of government debt amid declines in global stocks and concern that US economic growth is slowing.Ten-year note yields dropped to the lowest since December as a plunge in stock markets in Asia, Europe and the US wiped out more than $1.5 trillion from the value of global equities. The premium investors demand to own high-yield, high-risk corporate bonds and emerging market debt over Treasuries rose.

“People woke up and thought about risks they’ve been taking,” said Henley Smith, fixed income manager at Castleton Partners in New York. “As a result, Treasuries are moving up.”

The price of the 4 [5/8] percent security due in February 2017 rose 1 1[2/3]2, or $13.75 per $1,000 face value, to 101, according to bond broker Cantor Fitzgerald LP. The yield fell 17 basis points, or 0.17 percentage point, to 4.50 percent, the biggest weekly drop since the five days ended September 22.