Hershey's stock has taken a tumble.

Wall Street isn't biting into Hershey's (HSY transformation from a chocolate maker to a snack maker, at least not yet. 

Shares of the iconic producer of Hershey's Kisses tumbled 3.5% to $95.86 on Tuesday as UBS slashed its rating to sell with a price target of $90.00. The move to the downside was pretty convincing as it came on trading volume that was more than six times the 20-day average, according to Bloomberg data. Hershey's stock is now down 11% over the past 52 weeks compared to a 12% gain for S&P 500

UBS analyst Steven Strycula didn't pull any punches in his brutal downgrade. He thinks Hershey is overexposed to slowing demand for chocolate and intensifying competition from rivals Mars and Mondelez (MDLZ . Cocoa's 29% price surge this year also doesn't help Hershey, says Strycula.

Source: TheStreet
Source: TheStreet

For Hershey, the stock's performance has to be a disappointment for CEO Michele Buck, who took the helm at the chocolate maker in March 2017. Under Buck, Hershey has tried to pivot toward more snack-like treats for consumers, for example trail mixes with bits of the company's well-known chocolate. Wall Street has feared that the product shift could weigh on Hershey's longer-term profit margins as snacks are often less profitable than selling straight chocolate. 

More recently, Buck went all in on her play on snacks with the acquisition of Amplify Snack Brands Inc. for $1.6 billion. Hershey's big buy expands its portfolio further into the snacking aisle with Amplify's popular brands such as SkinnyPop and Tyrells chips brands.

"It's very exciting," Buck told TheStreet in an interview when asked about the deal last December. "As I took over on March 1 as CEO, I laid out the vision of innovation around being a snacking powerhouse -- this is a key step in us achieving that vision."

Wall Street looks like it's not sold just yet.