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.