Rarely has such major significance been attached to 10 basis points.

Since he took office in April, Bank of Japan Gov. Kazuo Ueda has been considered a skeptic of negative interest rates. Despite a recent eye-popping rally in the yen driven by expectations of a quick demise for this unusual setup, the central bank should feel under no pressure to quit the practice of penalizing people for saving. Prizes aren’t awarded for haste, as the governor knows from his own past.

The recent extraordinary yen advance — from around ¥147 to ¥141 versus the dollar in less than a day — is the kind of action you’d expect to see during a natural disaster, not a change from effectively zero to absolutely zero. Ueda’s predecessor, Haruhiko Kuroda, pushed the BOJ’s main rate down to minus 0.1% in 2016. The current chief has chipped away at some of Kuroda’s other easy money tools, often catching investors unawares, so returning borrowing costs to the black looks like a natural next step.

There’s a lot of potential to get things wrong — for traders as well as for Ueda. It seems clear that the governor would like to end the experiment. Whether he has the leeway to do so or get the timing right if he does is something else.

Investors seized on remarks this month by Ueda and a top lieutenant to conclude a shift was imminent, perhaps as soon as the board meeting that wraps up on Tuesday. Subsequent reports that officials at the central bank see little need to rush a decision have unwound a lot of bets on how "live” the conclave will be.

All this highlights the difficulty in interpreting what the bank may or may not be signaling. Ultimately, we don’t know what Ueda meant by his remarks on the "challenging” environment expected from year-end onward. Will it be hard because of his actions or external factors caused by economic changes overseas?

The jaw-dropping scope of the yen rally also says much about the world beyond Japan’s shores. While governments and central banks like to profess that domestic conditions are paramount, there’s more than deliberations in Tokyo. Investors caught a whiff that one of the dominant trends in foreign exchange this year was headed for retirement.

But that wasn’t just because some BOJ brass were talking. The currency action also reflects a growing sense that the game has changed abroad. The yen has been languishing not just because of easy money in Japan but because the other big central banks were tightening. That story is winding down. The question has moved quickly from how long will the Federal Reserve hold rates high to when will it cut? Same with the European Central Bank.

The prior BOJ meeting highlights how tricky this communication — and misinterpretation — has been. One commonly held consensus view from October’s gathering was that a Nikkei report some 12 hours before the decision signaled a hawkish tilt and the BOJ delivered something more dovish.

We disagree. While some have disputed the scrapping of fixed-rate operations as a minor tweak, former BOJ chief economist Hideo Hayakawa was on the mark when he told Reuters that the move effectively dismantled yield-curve control. The prior ceiling of 1% on 10-year government yields was downgraded to merely a "reference point.”

Hayakawa is an authoritative voice who foresees the first rate increase in April. There’s much to be said for not rushing to jettison negative rates this month. Ueda doesn’t have to get everything done by year-end. He could do worse than recall an earlier version of himself, the Ueda who sat on the BOJ board a generation ago during a contentious time.

When BOJ officials gathered in the late summer of 2000, the economy was coming back from what was then a decade-old funk and the risk of deflation had diminished. A majority felt there was sufficient momentum to end a radical period of ultralow rates, and markets had anticipated such a step. Ueda was one of two lonely voices who questioned the proposal that August. He took the rare step of formally dissenting. (Nobuyuki Nakahara also broke with the majority.)

Ueda’s argument at the time was a subtle one. He agreed the economy was moving in the right direction. He also felt there was no harm in waiting just a little longer. That version of Ueda was correct. The hike in August 2000 is now widely perceived as a fiasco and had to be reversed the following year.

How much of that lesson will guide Ueda remains to be seen. It’s not a bad thing that the FX hysteria has subsided. We just need a bull market in patience.

Gearoid Reidy and Daniel Moss are Bloomberg Opinion columnists.