Folk artists on stilts practice ahead of a performance to celebrate the traditional Chinese Spring Festival on the second day of the Chinese Lunar New Year. Reuters China is spending cash on three fronts to prop itself up.

It's plowing foreign exchange reserves into stabilising its currency, pumping money into the stock market and boosting government stimulus to support economic growth.

It can probably do this at least until 2020, barring any major crises. China needs to buy itself time to transition from rapidly catching up with developed economies to stable, domestic demand-led growth.

So here are the numbers:

China had $3.65 trillion (£2.3 trillion) in foreign-exchange reserves at the end of July. Analysts surveyed by Bloomberg think that it will cost the country around $40 billion (£26 billion) a month to intervene and support its currency. The report cited analysts as saying:

“China has paid and will keep paying relatively significant costs to maintain the yuan’s strength,” including sacrificing exports and using foreign-exchange reserves, China Securities Co. analysts Huang Wentao and Zheng Lingyi said in comments on Aug. 11. “Economic fundamentals don’t support a steady yuan.”

Meanwhile, the stock market is going absolutely bananas. The benchmark Shanghai Composite, fell by more than 5% in early trade today – something that took its losses to more than 11% from Monday’s close. However, it somehow finished the session up by 1.24%.

The Chinese stock boom in the past few years was backed up by debt-fueled share-buying. The debt, or margin, is now dropping sharply as people are waking up to the fact that they can lose more money than they put in. As speculators pull back, the government intervenes.

This chart from Macquarie shows just how high that debt went, relative to other stock booms, and how far it could fall:

The rate of government buying to keep stocks up isn't disclosed but estimates from Bridgewater Associates put the ammunition available at around $500 billion (£318 billion).

Lastly, the Chinese government just injected nearly $100 billion (£63.7 billion) from its foreign exchange reserves into two policy banks, which lend on state orders to boost the economy.



If China cracks open its piggy bank and spends like this consistently, it will take around five years to exhaust the reserves. These are just rough estimates, and the information to make accurate judgments isn't always available, but it gives a sense of the firepower China has at its disposal.

Despite this, if China wants people to invest and growth to pick up again then it needs to instill confidence. Blowing its savings propping up markets distorts real prices but doesn't do much to change intrinsic value, which is what long-term investors really look for.

China can buy a lot of time, but credibility is harder to come by.