UPDATED with closing price. Shares in AMC Networks have sagged more than 10% over the past week as Wall Street analysts scrutinize The Walking Dead and what the sizable ratings decline for its ninth-season premiere says about the company’s prospects.

Goldman Sachs downgraded AMC to a sell from a neutral rating late last week, and yesterday the stock fell more than 7% after the premiere numbers were released. Today, on a brutal day on Wall Street, AMC Networks stock closed at $57.65, down nearly 4%, on above-average trading volume.

Ratings for Sunday’s episode tumbled 47% in total viewers and 50% in the 18-49 demo compared with last year’s premiere, returning the show to viewership levels last seen in 2011.

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Today, another caution flag on AMC was thrown by Guggenheim’s Michael Morris, who cut his 12-month price target to $58 from $60 and lowered estimates for advertising revenue. Morris retains his neutral rating on the company.

AMC stock entered Wednesday at $59.96, the first time it has dipped below $60 since July. In 2018 to date, though, they have gained almost 15%.

In his report, Morris noted not only the ratings decline for TWD but also the disconcerting reality that, as he puts it, “the live television audience continues to age.” He estimates 18-49 viewership comprised 53% of the total audience on Sunday, down from 55% on average for Season 8 and 66% over Season 3 in 2012-13.

“Combined, we are concerned that overall audience declines and the aging of that audience could put more pressure on the company’s advertising revenue trends than is currently appreciated by investors,” Morris wrote. “While the company has made significant progress in diversifying its advertising base (expanding the slate of original programming, acquiring a consolidated interest in BBC America) we continue to believe that The Walking Dead is a significant contributor to total company revenue.”

Although AMC for the first time made TWD available on its $5-a-month premium service AMC Premiere, the move brought a “clear tradeoff,” according to Morris. The company is balancing “the long-term value to AMC Networks of developing the direct-to-consumer offering” with “a short-term advertising sacrifice.” But subscription revenue in the near term will not make up for the advertising declines, Morris predicts.

However, the analyst went on, “were these subscribers to remain with the premium service outside of TWD season and increasingly engage with the company’s other original programming, we see the potential for a value-enhancing shift that is not reflected in the current share price.”