Policy tightening by the Bank of Japan, the last bastion of ultra-low interest rates, may send shock waves through the financial world. Lift-off could be at hand, according to T. Rowe Price.

“Japanese monetary policy could be the San Andreas fault of global finance,” Arif Husain, head of international fixed income and chief investment officer at the $1.3 trillion fund, wrote in a report. “I know the BOJ is conscious of the effect it could have on global markets, but it’s a real and present danger, in my view. I certainly think it’s something that should be on our radar as investors.”

Husain joins BlackRock Inc. and the European Central Bank in warning that the BOJ’s policy normalization may send a wave of Japanese cash flowing out of global markets toward home. The stakes are high: Japanese investors have splurged more than $3 trillion on offshore investments after being bludgeoned by years of negative rates. The great withdrawal may already be under way, with Japanese investors selling a record amount of European debt last year, according to data compiled by Bloomberg.

A $3 Trillion Threat to Global Financial Markets Looms in Japan

Husain said the last anchor of quantitative easing “may be about to give way”, and recent history gives his warning credence. Japan’s central bank relaxed its grip on its tightly controlled 10-year bond yield by a fraction last December — a move that jolted everything from Treasuries to the Australian dollar.

Global bonds once again came under pressure this week after surprise rate hikes by Bank of Canada and the Reserve Bank of Australia, which may renew pressure on the BOJ to tighten. Yet signals from the futures market suggest foreign investors are unprepared for any significant BOJ shift.

A Bloomberg survey shows BOJ watchers pushed back their forecasts for the timing of policy adjustments to July and only a third of respondents expect it. That’s because of Governor Kazuo Ueda has repeatedly signaled the need for continued monetary stimulus.

“If the BOJ lifts its yield curve controls, it could end up being a lot more important for markets than whether the Federal Reserve hikes or cuts rates at its next meeting,” Husain wrote. An exodus of global funds from the Asian nation could deliver a “significant shock to markets outside Japan.”