The dollar drifted up from multi-month lows on Tuesday, while the yen was perched near seven-month highs as investors held their breath for a potential policy shift at the Bank of Japan.

The euro reached a nine-month high on Monday at $1.0874, but was last loitering around $1.0811.

The yen hit a top of 127.22 per dollar during Asia hours on Monday, before easing a little during a holiday-thinned U.S. session to sit around 129.10.

Speculation is building about a change or end to Japan’s yield curve control policy, given that the market pushed 10-year yields above a ceiling set by the Bank of Japan (BOJ) of 0.5% on Friday and Monday and the amount of bond buying to defend it is starting to look unsustainable.

A newspaper report last week has also stoked expectation for a change, so traders are on the lookout for a sharp reaction even if the BOJ makes no move at its two-day meeting ending on Wednesday. The yen rose 3% against the dollar last week, and one-week implied volatility for dollar/yen is at its highest since March 2020.

“The market has run pretty hard with this story and is looking for a follow up,” said Tony Sycamore, an analyst at brokerage IG Markets.

He sees three main possibilities: no policy change, a tweak similar to a move in December to widen the 10-year yield target band, and the total abandonment of the yield curve control policy, with the latter likely to drive the most extreme market response.

“The yen would explode higher, Japanese government bond yields would explode higher and global yields would go higher,” he said.

Elsewhere, the U.S. dollar index bounced from a seven-month low of 101.77 made a day ago and held at 102.52. Sterling touched its highest since mid-December at $1.2288 before easing back to $1.2192.

There was not a great deal of currency market reaction to stronger-than-expected Chinese growth data.

At 2.9% fourth-quarter year-on-year growth was far stronger than the 1.8% consensus forecast, helped by retail sales falling a lot less than feared in December. Economists said that bodes well for recovery, but markets were less sure about how to take the surprise and sent the yuan a little bit lower.