The yen gained on Monday amid broad weakness in the dollar as traders remained on heightened alert over Japanese intervention to halt the currency’s recent slide.

The Japanese currency jumped as much as 1.2% versus the dollar, extending Friday’s gain.

The Bloomberg Dollar Spot Index slid to the lowest level since September after a rate check Friday by the Federal Reserve Bank of New York spurred speculation the U.S. might assist Japan in efforts to weaken the greenback versus the yen.