I think some prices in china are due to the withdrawal issue (you can withdraw in cash, not in btc - so you sell the btc to get your cash).
Not sure if they've allowed normal withdrawals.
This case is long gone, btc withdraws were blocked only on okcoin.cn not okcoin.com, and the block was shifted like a month ago.
$200 dollars gap between some of main exchanges(okcoin- finex)
this is madness
There is 100$ difference between weekly OKC contracts and finex, where did you get that 200 from?