Cocoa futures saw the biggest monthly advance in more than two decades in New York on the back of mounting supply fears that threaten to push prices of the key chocolate ingredient even higher.

Futures gained 25% in February, marking the biggest monthly gain since 2001, as bad weather and disease hurt crops in West Africa, where most beans are grown. Prices also reached fresh records this month, hitting an intraday high of $6,648 per metric ton on Monday.

“Trading at all-time highs makes for extremely volatile action,” analysts at the Hightower Report wrote in a Thursday note.

Cocoa’s surge is raising the cost of making confectionery — which risks being passed on to consumers.

Switzerland’s Barry Callebaut, which supplies some of the biggest consumer chocolate brands, expects cocoa production to trail consumption by 500,000 tons in the current season. Another deficit of 150,000 tons is expected the following season. West African farmers lack the incentive to expand output, it warned.

“For now we don’t see any recovery in the supply,” Hugo van der Goes, the company’s vice president for cocoa in North America, said at the International Sweetener Colloquium on Wednesday. “The supply shortfall is just way bigger than what we see on the demand destruction side.”