Last year, one of the great hedge fund trades was to borrow yen, lever those yen up to five times and invest in renminbi. Investors made money on the appreciation of the Chinese currency in addition to receiving a higher rate of interest than they could on most other currencies in a world of easy money and zero rates.

The trade was also in line with government policies in both countries. Tokyo was committed to driving down the value of the yen, while Beijing favoured a gradual appreciation of the renminbi. That meant there was no volatility, making the trade even more attractive on a risk-adjusted basis.

Since February, that happy trade is a thing of the past. The Chinese government, citing its desire to end such one-way bets, has shifted course, driving the renminbi down 3 per cent but still way above its level of a few years ago.