Crude oil is the top most liquid equipment or best property on the stock market. Because for today the Light-sweet Crude Oil is now trading flat at Rs 6,351. The counter has seen trades of around 1,975 contracts, while, the open interest has increased by 739-odd lots. So Invest on Crude oil and find best thing what you want.

broad answers. probably have to go with stock. equipment is hard to sell and so is property. and product can also take a while to reach market

If this is an accounting question and by stock you mean held for; Investment - Short Term Trading, then stock.

If the stock is being held for strategic reasons or you mean the company's stock then, Inventory, or Product.