1) Buy in 2) Buy too much 3) Stock 4) Stock excessively 1) Glut 
Overstock, excessive stock, B-stock, or excess inventory, is the result of poor management{dubious|date=October 2010} of stock demand or of material flow in process management. Excessive stock is also associated with loss of revenue owing to additional capital bound with the purchase or simply storage space taken. Excessive stock can result from o...
• (n.) Stock in excess. • (v. t.) To fill too full; to supply in excess; as, to overstock a market with goods, or a farm with cattle.
An excessive amount of product purchased in anticipation of increased sales volume. 
O'ver·stock` noun Stock in excess. Tatler. O`ver·stock' transitive verb [ imperfect & past participle Overstocked ; present participle & verbal noun Overstocking .] To fill too full; to supply in excess; as, to overstock a market with goods, or a farm with cattle. 
[v] - stock excessively
to stock to excess: We are overstocked on this item.