Capital stock is the number of common and preferred shares that a company is authorized to issue, and is recorded in shareholders' equity. Capital stock, also known as authorized stock, refers to all common stock and preferred stock a corporation is legally allowed to issue.This form is for general instructions that apply to all corporation tax forms. It includes a variety of topics about how to fill out your form. What is capital stock? 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. It is usually issued when companies are trying to fund their growth. Find out why Stony Brook University has become an internationally recognized research institution that is changing the world. At Norfolk Southern, we are dedicated to moving America forward. Capital stocks are the shares outstanding for a company.