On holiday on the Caribbean island of Mustique, Philippe Jabre woke up in the middle of the night – as is his habit. It was the day after Easter Monday and Japan’s Nikkei index had fallen by 5%. He quickly decided it was a buying opportunity.

According to Jabre, one of Europe's best-known hedge fund managers, the markets were nervous about a forthcoming policy announcement from the Bank of Japan governor Haruhiko Kuroda, who had assumed office the previous week.