For all we know a few choke point suppliers could say let's be like De beers and manufacture more scarcity of something like Neodymium or further down the supply chain buy most of a resource up and sit on it.
Uncertainty of the future supplies could have some companies stockpiling materials so they can keep up with their contracts and not worry about more COVID disruptions to their own operations.
I'm not saying any of that is real but generally there is no public knowledge of supply chain. The secrecy of sales leads, output, and prices might be the only thing keeping them from being undercut or priced out by another company.
Also all the stock market woes for a company if the public found out their output is crippled ahead of any shareholder reports.
Maybe you can get data from something state owned or a trade group insider news?
