Beijing swells dollar reserves through stealth

China has resorted to stealth intervention in the currency markets to amass US dollars, using indirect means to hold down the yuan and ease the pain for its struggling exporters as the global slowdown engulfs the economy.

A study by HSBC's currency team in Asia has concluded that China's central bank is in effect forcing commercial banks to build up large dollar reserves, using them as arms-length proxies in a renewed campaign of exchange rate intervention.

Beijing has raised the reserve requirement for banks five times since March, quickening the pace with two half-point rises in late June.

This is having major spill-over effects into the currency markets because banks in China have been required over the last year to hold extra reserves in dollars rather than yuan. The latest moves have lifted the mandatory deposit from 15pc to 17.5pc of total lending since March.

"China has used the pretext of reserve requirement hikes to help slow yuan appreciation. We estimate that the PBOC [central bank] intervened by about $49.6bn in June," said Daniel Hui, the bank's Asia strategist.

Beijing has also slashed the amount of foreign debt banks operating in China can hold. The effect is to oblige the banks to become net buyers of dollars, halting the flow of foreign "hot money".

Given the sheer scale of China's foreign reserves - now $1,800bn (£970bn) - any shift in its exchange policy now ripples around the globe. The covert buying may help to explain at least part of the explosive dollar rebound over recent weeks. The closely watched Dollar Index reached an all-time low in March. It crept up gradually in the early summer before smashing through resistance in July. The world's currency system is swivelling on its axis. Central banks in Asia and Europe have stopped raising rates, and some have begun to cut aggressively. The Federal Reserve is no longer nakedly exposed. Indeed, investors are already starting to look ahead to the next round of Fed tightening. The 18pc slide in oil prices from a peak of $147 a barrel in July has added juice to the dollar rally. Russia and the Middle East petro-powers tend to recycle a high proportion of their vast earnings from oil into the eurozone, either by purchasing European bonds or expensive imports. A Bundesbank study found 40 cents of every dollar spent by eurozone countries on oil imports comes back again one way or another. The figure for the US is just 10 cents. This trade bias has given oil a new character as a sort of anti-dollar driving the currency markets. Even so, the China effect is a key ingredient in the dollar comeback. Beijing's Politburo is clearly disturbed by the sudden downward turn in the economy as export markets freeze, and surging wage inflation in the country's manufacturing hubs eats away at profit margins.