Technicians of AMD, the world's second-largest maker of computer microprocessors after Intel Corp, display wafers for the media in the eastern German city of Dresden. Reuters/Arnd Wiegmann Betting against AMD this year has been unprofitable, but that's not stopping investors from jumping on the trade.

Short interest, or bets that the semiconductor manufacturer's stock price will fall, rose to an all-time high this week, according to the financial-analytics provider S3 Partners. The shares sold short rose to 159 million shares, or an estimated 18% of those available for trading.

That leaves plenty of room for those who still want to jump on the bearish trade, despite the trade losing 6.6% this year, or about $110.3 million.

AMD gained 10% this year through Monday's market close, and an incredible 84% over the previous year. The growing popularity of cryptocurrencies including bitcoin has boosted demand for its graphics chips used for mining.

But because cryptocurrency prices are very volatile, they are not a reliable source of revenue for AMD, according to Barclays. The company itself acknowledged in July that cryptocurrencies were not a long-term driver of growth.

This makes it important for AMD to gain market share from its competitors, particularly Intel and Nvidia.

Among the three companies which have increased in market value this year, only Nvidia's short interest fell as its share price rose, S3 said. Short sellers are down 58% on the bet against Nvidia this year.