We break down the biggest gainers and droppers in the Cheddar 50 index this year, plus one Japanese stock that's made a big splash in the U.S. in 2017.

On the plus side, shares of Square have risen about 160 percent this year as the digital payment company has expanded into new markets. And video game maker Take-Two Interactive has also more than doubled in 2017, as investors and fans both await the release of Red Dead Redemption 2 this spring.

But they weren't all winners. Pandora shares were down more than 60 percent as the music streaming service struggled to grow paying subscribers. And Blue Apron stock has dropped as much as 70 percent since its IPO in late June, losing its CEO and cutting jobs.

Plus, what about Japan's SoftBank? The tech holding company launched its $100 billion Vision Fund, which has made investments in Nvidia, WeWork and Flipkart. And we're still waiting for what could be a $10 billion investment in Uber.