This is bad reporting. The amounts are too small to be meaningful in the currency markets.
In addition, China has enormous interest in maintaining the dollar as the reserve currency. Keeping the USD as reserve currency allows the US to borrow at very low rates, and borrowing at low rates is a pillar of its debt-driven economy. The US debt-driven economy is what makes a market for Chinese exports. And China's economy is basically exports plus infrastructure investments by state-owned enterprises. Take away the US for the exports and China has a huge problem. That's why it buys so many Treasuries.
There's also an argument to be made that the yuan is over-valued. It took a nose-dive when China briefly removed currency controls (last year?) because a lot of people wanted to move their money out.
In addition, China has enormous interest in maintaining the dollar as the reserve currency. Keeping the USD as reserve currency allows the US to borrow at very low rates, and borrowing at low rates is a pillar of its debt-driven economy. The US debt-driven economy is what makes a market for Chinese exports. And China's economy is basically exports plus infrastructure investments by state-owned enterprises. Take away the US for the exports and China has a huge problem. That's why it buys so many Treasuries.
There's also an argument to be made that the yuan is over-valued. It took a nose-dive when China briefly removed currency controls (last year?) because a lot of people wanted to move their money out.