What happened

Shares of Overstock.com (NASDAQ:OSTK) gained 35.7% in December 2017, according to data from S&P Global Market Intelligence. By and large, the online retailer tapped into surging cryptocurrency markets.

So what

Overstock is a well-known early adopter of blockchain technologies. The company has been accepting retail-level payments in bitcoin since 2014, and Overstock's own research and development of blockchain-based technologies has hatched a new platform for trading of stocks and other financial instruments.

So it's not surprising to see Overstock shares surge in a month where bitcoin prices peaked just below $20,000 per coin, up from $1,000 at the end of November. When the bitcoin, Ethereum, and Litecoin mania took a step back in the middle of the month, so did Overstock's share prices.

Businessman studies a wall-sized poster of a simple blockchain illustration, titled BLOCKCHAIN in capital letters.

Image source: Getty Images.

Now what

The tight bond between bitcoin prices and Overstock's shares is real. In December, CEO Patrick Byrne announced a low-cost stock trading platform built on blockchain transactions, right after telling investors that he might want to sell Overstock's e-commerce operations to pour that windfall into more cryptocurrency and blockchain business ideas.

So investors are largely forgetting about Overstock's online retail operations to focus on the company's crypto-tech future. If you want to bet on the success of bitcoin and friends without actually owning any coins, Overstock could be a good way to get started. Or, if you're a cryptocurrency skeptic, you might want to stay far away from this stock until further notice.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.