Chinese foreign exchange reserves fell by another $69 billion in November, if reserves continue to fall, then the impact on the global economy may be huge.

The rise of China has probably been the most significant economic development so far this century. It has helped lift nigh on a billion people out of poverty but has coincided with one of the more troubled periods for developed economies across the world in decades.

Is this a coincidence, or is there a cause and effect relationship?

Certainly, many US politicians blamed China's policy of maintaining a cheap currency, the yuan, for some, maybe even most, of the ills pertaining to the US economy.

But those days are gone. These days China has been throwing money at trying to stop the yuan from getting cheaper. In short, it is doing the opposite of what it had been accused of for many years.

And total foreign currency reverses have fallen by some $1 trillion over the last two years, or by some 25%. In November, the sell-off seemed to gather pace.

It may have been a one-off, a Trump effect. For sure, authorities in China seem unperturbed.

But this sell-off may be more significant than is commonly realised.

When China was indeed trying to stop its currency from rising, it managed this by taking Chinese savings to buy foreign exchange, in particular: US bonds. This may have been an underlying cause of low-interest rates this century.

Now this force has gone into reverse. Does this suggest we may have seen the reversal of one of the main drivers of record low global interest rates?