This is why stock trading isn’t for the faint of heart.  Netflix shares are up more than 81% so far in 2015, and touched an all time high today — $628.50. Its market value is higher than Dish Network, CBS, Viacom, and Twitter. So you might think it’s fully priced.

But hold on: Pivotal Research Group’s Jeffrey Wlodarczak is turning heads today with a report in which he raised his target price by $200 to a whopping $850.

That’s driven in part by his optimism about CEO Reed Hastings’ ability to drive the company into new markets including China. The analyst also says that Netflix “remains a takeout candidate for a large Internet player” such as Amazon, Google, Apple, or Alibaba.

In any case, Wlodarczak believes there’s a lot of room for growth: Netflix could have 160 million customers worldwide by 2021, which is 15.9% more than he previously envisioned. International territories account for 95 million of the expected subs, up 21.8% from his earlier forecast.

The analyst adjusted his numbers after adding China and South Korea to his forecast. Netflix’ talks with a potential Chinese partner should pay off, he figures, giving the company 13.5 million subs there — equal to 5% of broadband households — by 2021. He believes South Korea will add 2.5 million customers, or 12.5% of the potential market.

Content costs will have to rise. But the company can make up for that with “limited price increases.” All told, the company could generate more than $40 in earnings per share by 2021, he predicts. You get to his $850 stock price if you figure the present per share value of the expected cash flows, and then multiply by 20 (he previously used a multiple of 17).