The current shortages seem to be driven by lower production in West Africa [1] (which accounts for two-thirds of the global crop), not by speculation.

The reasons for the lower production include drier weather due in part to climate change, a resurgence of the swollen-shoot disease that affects cocoa plants, and illegal mining affecting land on which cocoa is grown.

[1]. https://www.fastcompany.com/91065690/cocoa-beans-production-...