The Japanese yen experienced a significant surge against the U.S. dollar in early Monday trading, reaching the 154 level. This sharp appreciation follows reports of a "rate check" conducted by the New York Federal Reserve, signaling potential intervention efforts.

• The yen jumped by nearly 4 yen to the lower 154 zone against the dollar.
• The New York Federal Reserve reportedly conducted a "rate check" with major banks last Friday.
• This move by U.S. authorities, while not an intervention, is seen as a stronger signal that Japan and the United States may be collaborating to prevent further weakening of the yen.