Nvidia just took a one-two punch from Wall Street (NVDA)

Nvidia is sliding after two Wall Street firms took shots at the company.
Goldman Sachs and Citron Research both announced a pullback on their optimism while maintaining a good overall outlook.

Nvidia's short-term future is looking bleak.

The stock is down 1.52% to $236.84 after Goldman Sachs removed Nvidia from its conviction list, and Citron said the stock is about to drop about 15% to $200.

The two firms are both concerned about how red-hot Nvidia shares have been recently. Shares have been on a meteoric tear over the last year, gaining 104.31%, as revenues grew just 11%. In 2018, stock has posted a 16.74% gain, which Citron thinks is too much.

"Is Nvidia really worth $36 billion more than it was New Years Eve with $15k BTC?" Citron asked on Twitter. Nvidia has gotten a boost from cryptocurrency miners buying huge numbers of graphics cards to speed up their rigs, especially as the price of bitcoin hit its high of nearly $20,000 in December. Prices have come crashing down to just under $9,000, which could mean demand from miners could wane.

Citron and Goldman both fear the boost Nvidia has seen from cryptocurrency mining is unsustainable and unreliable as a way to grow sales. Goldman said it could lead to volatile earnings as Wall Street struggles to find concrete ways to predict the demand of the crypto market.

For context, during its recent earnings call, AMD's leadership said crypto mining added about $300 million in revenue, or about 5-6%, in 2017. Nvidia is set to report its earnings, and its boost from crypto mining, on February 8.

Crypto isn't the only worry for Nvidia, though.

The company's data center business was just starting when Goldman added the stock to its conviction list in late 2016. Since then, it's exploded as artificial intelligence and cloud computing have become the hottest new trend in enterprise computing. The sector is now better understood, which means more players are starting to nip at the heels of Nvidia's dominance, according to Citron.

Citron said that Nvidia used to be the only player in AI and autonomous driving computing, but is facing stiff competition in both categories going into 2018.

While both Goldman and Citron criticize the company and predict a more difficult 2018, the firms agree that Nvidia is still at the top of its game. Goldman maintained its buy rating on the company, and Citron said it still loves the company's CEO, Nesen Huang. 2018 may just be a slower year for the company.

Nvidia is up 16.74% this year.