At first glance, it looks like the biggest conundrum in global markets. Foreign investors have for years consistently increased their holdings of Japanese government debt. Their share of this market, on which yields are minimal or negative thanks to the Bank of Japan’s quantitative easing policy, stands at more than a tenth.

How do we explain this counter current to the tide of deglobalisation, this enthusiasm for what must objectively be seen as one of the world’s least attractive government bond markets — especially when resident investors have been investing heavily in foreign assets since the central bank embarked on the latest round of QE in 2013?