buffer stock
noun [ C or U ]
ukus ECONOMICS, FINANCE
a large supply of a commodity (= a crop, metal, fuel, etc.) that is bought and stored when extra is available, and sold when there is not enough, in order to control its price and quantity in the economy:
Rubber prices fell to a four-year low, despite purchases for the buffer stock.
COMMERCE, PRODUCTION
extra products, supplies, etc that a company keeps, so it always has enough available to sell or use:
Management wants to keep a buffer stock of 500 units.