Did China do something that made the Chinese people start buying? Or what?

And how did you know or come to the conclusion that it is the Chinese people buying bitcoin?

Anyways, I think the first comment already said it all, some companies, prominent names recently started applying for bitcoin ETF, and I personally believe that to be the major reason why the price of bitcoin suddenly jumped to $30,000, it is the second time in this year that bitcoin has reached the price of $30,000, the first time it did, it later dropped back down to the recent low of $25k, but this time, i am hoping it stays above the $30k mark until a major bull run comes, hopefully.
There is even a news that states Bitcoin spikes to as much as $138k on crypto exchange Binance.US, it was a short lived though since it goes back to normal as soon as it spiked that much. It was told to be a liquidity issue between the pair BTC against Tether.[1]
Well, it looks like the Bitcoin ETF and the US announcement of the new exchange really push the price of Bitcoin up[2], after the Binance and coindesk issue which make BTC to plummet. Bitcoin did it again, surprising and shaming TA's on their prediction about BTC crashing further.