In trading and investing, stock refers to a financial security that denotes ownership in an underlying corporation. The stock is broken up into shares, which are easy to exchange over the stock market, or in private sale. By owning shares of stock in a corporation, the holder is entitled to ownership rights of the corporation, which includes a right to participate in earnings and asset value growth of the company. This is why investors buy stock, hoping the value and income of the underlying corporation increases. Holders of common stock are also entitled to vote on company matters, either by attending annual and special meetings or by sending their vote by proxy, if they are a holder on the day of record.
The percentage of the corporation that one share of stock represents is different for every corporation, and depends on the total number of shares outstanding. If there are 10 shares outstanding and a holder owns 1, he owns 10% of the corporation. If there are 100,000,000 shares outstanding and the holder owns 1, he owns 1/100,000,000 (one one-hundred millionth) of the total corporation.
The shares that day traders exchange are in publicly traded corporations. Day traders should be very happy that stock exists, as it makes it extremely easy to exchange small fractions of corporate ownership in thousands of corporations. Publicly traded corporations are governed by the SEC, and holders have rights and limitations that may differ from privately held corporations.
While owners of stock are allowed to profit in the growth of a company, their liability for debts incurred by the corporation do not extend beyond their initial investment. In the event of a bankruptcy, holders of the corporate stock are generally the last in security ownership line to receive any payment from the sale of all assets. Some investors, and even some traders, will buy preferred stock in a corporation. Preferred stock differs in that there are not typically voting rights associated with it, but in the event of a bankruptcy holders of preferred stock are ahead of the common stock owners in claiming a right to any value from the liquidation of the corporation. Preferred stock may also receive a different yield in dividend payments, and are entitled to the rights to dividend payments before holders of common stock.
Traders should keep in mind that the stock they are trading represents real tangible value in the underlying corporations. The nature of public stock and the public markets has made rapidly facilitating their exchange very easy, and without this day traders would not be able to function.