Capital stock is the number of common and preferred shares that a company is authorized to issue, and is recorded in shareholders' equity. In economics, "Capital" means any material quantity that has value, and using which brings revenue to the business.The capital stock is an important source of propagation in slumps, a point that has escaped analysis in the cycle-around-trend view of fluctuations. It is the total amount of physical capital at any particular moment in time. Capital is one of the factors of production. Capital stock is the total amount of shares a company is authorized to issue, while treasury stock is the number of shares a company holds in its treasury. Economics, business, accounting, and related fields often distinguish between quantities that are stocks and those that are flows. Capital markets are financial markets that bring buyers and sellers together to trade stocks, bonds, currencies, and other financial assets. Capital stock are equity holders in the company. There's a problem with that, though: physical capital rusts.