phew almost got trick
i don't know why you say Yuanbao is one of biggest chinese exchange.

Volume of Yuanbao looks very small. Same level as Bittrex

 

https://coinmarketcap.com/exchanges/yuanbao/


And if you check with Wiki, you can't even find an article for the exchanger. Of course, you will find a page for Okcoin on Wiki

seem like Yuanbao is just a tiny/unpopular chinese exchanger