(Bloomberg) -- Cocoa climbed to the highest since February in New York as Hershey Co. was said to take the unusual step of buying beans through the exchange rather than the physical market.

The trade, which this week sent December futures to a record premium over the March contract, comes after top cocoa growers Ivory Coast and Ghana added a large premium for their beans in a bid to increase farmer incomes. Buying through the bourse is cheaper because those supplies don’t incur the premium.

Read more: Hershey Is Behind the Big Cocoa Trade That Upended N.Y. Markets

March futures climbed as much as 2.8% to $2,739 a ton in New York, reaching the highest for a most-active contract since late February. The contract is up 16% this week, the most since it started trading in 2019. December futures reached a premium of as much as $275 over March prices this week.

“With Hershey somewhat circumventing the LID price and taking the New York futures market by surprise, it’s completely upended the structure,” said David Cutler, vice president of soft commodities at R.J. O’Brien Ltd. in London. “Taking more than the total U.S. certified stocks and some leaves the short position holders in a difficult state. The structural change in the market has forced shorts tocover and triggered momentum buying.”

Hershey said it doesn’t discuss details of its buying and hedging activities and that it purchases cocoa from a variety of suppliers and sources to meet its needs.

The 14-day relative strength index for New York cocoa has exceeded 70, indicating that the market could be set for a pullback. Before the recent rally, prices had been pressured by concerns that the coronavirus pandemic will hurt out-of-home demand and contribute to a global surplus.

In other soft commodities:

• Sugar declined in New York and London.
• Arabica coffee fell, while robusta rose.

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