Advanced Micro Devices Inc. shares closed in negative territory for the year Monday after an analyst voiced doubts about the chipmaker’s potential for growth, especially in gaming and cryptocurrency, adding to a sharp four-day decline since the company reported earnings last week.

AMD AMD, -0.30% shares dropped 8% to close at $10.89 and ranked as the worst-performing stock on the S&P 500 index SPX, +1.05% Monday. More than 137 million shares exchanged hands by the close, more than double the 52-week average trading volume of 65.6 million shares.

In a Monday note, Morgan Stanley analyst Joseph Moore slashed his rating and price target, downgrading the stock to “underweight” from “in-line” and cutting his price target to $8 from $11, and expressed skepticism for the company’s growth potential in 2018.

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Moore said he had been skeptical ahead of last week’s earnings report that AMD could produce numbers that would justify its valuation. The report just confirmed for him that AMD’s PC business will have to shine to make up for struggles he expects in cryptocurrency mining and gaming consoles.

He writes:

We are now roughly in line with consensus, and in some respects the fundamental outlook is not quite as robust as microprocessor momentum has been slow to build, offset by cryptocurrency gains. We expect cryptocurrency to gradually fade from here, consoles to decline, and graphics to be flattish; we think that the core microprocessor business would have to grow by $880 mm just to hit Street numbers in CY18.

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AMD reported third-quarter computing and graphics revenue of $819 million, a year-over-year gain of 24%, about half of its $1.64 billion in total revenue for the period, and $2.07 billion for the first nine months of 2017, more than half of its $3.85 billion in total revenue for the period. Analysts surveyed by FactSet expect AMD earnings of 35 cents a share on revenue of $5.89 billion for calendar 2018.

Moore’s note wasn’t all negative. He continued:

To be clear, we admire what the company has accomplished on a fraction of its competitors’ budgets in both microprocessors and graphics—our cautious view is based entirely on the current stock price, and the limited potential for upside in 2018 and beyond.

Moore expects videogame console revenue, which he estimates to make up 36% of sales, to decline by 5.5%, and cryptocurrency mining sales, which he estimates to make up 9% of sales, to decline by 50% in 2018. He also expects gaming graphics sales, an estimated 21% of sales, to be flat.

Moore upgraded the stock from underweight on Dec. 14, 2016. Since then, AMD’s stock price climbed nearly 34% and then dropped off sharply following the chipmaker’s earnings report last Tuesday. Following that report, shares have dropped nearly 24%, and closed at their lowest level since early May.

Shares are trading down 4% for the year, compared with a nearly 40% gain in the PHLX Semiconductor Index SOX, +1.20% and a nearly 15% gain in the S&P 500 index. In late July, AMD had been up as much as 38% for the year, touching a 52-week high of $15.65.

Of the 32 analysts who cover AMD, 10 have overweight or buy ratings, 16 have hold ratings, and six have sell ratings. Their average price target is $14.21.