Trader is person or entity, in finance, who buys and sells financial instruments such as stocks, bonds, commodities, derivatives, and mutual funds in the capacity of agent, hedger, arbitrageur, or speculator.

Trading strategy - a fixed plan that is designed to achieve a profitable return by going long or short in markets. The main reasons that a properly researched trading strategy helps are its verifiability, quantifiability, consistency, and objectivity. The development and application of a trading strategy follows eight steps: Formulation, Specification in computer-testable form, Preliminary testing, Optimization, Evaluation of performance and robustness, Trading of the strategy, Monitoring of trading performance, Refinement and evolution. For every trading strategy one needs to define assets to trade, entry/exit points and money management rules. Bad money management can make a potentially profitable strategy unprofitable. Trading strategies are based on fundamental or technical analysis, or engage them both. Technical strategies can be broadly divided into the mean-reversion and momentum groups. There are also specific strategies, like "Sell in May and go away but remember to get back in September". Trading strategies are usually verified by backtesting, where the process should follow the scientific method, and by forward testing (a.k.a. 'paper trading') where they are tested in a simulated trading environment. Momentum signals (e.g., 52-week high) have been shown to be successful in trading strategies and are used by financial analysts in their buy and sell recommendations.

Trade - involves the transfer of goods or services from one person or entity to another, often in exchange for money. A network that allows trade is called a market. The original form of trade, barter, saw the direct exchange of goods and services for other goods and services. Barter is trading things without the use of money. Later one side of the barter started to involve precious metals, which gained symbolic as well as practical importance. Modern traders generally negotiate through a medium of exchange, such as money. As a result, buying can be separated from selling, or earning. The invention of money (and later credit, paper money and non-physical money) greatly simplified and promoted trade. Trade between two traders is called bilateral trade, while trade between more than two traders is called multilateral trade. Trade exists due to the specialization and division of labor, in which most people concentrate on a small aspect of production, but use that output in trades for other products and needs. Trade exists between regions because different regions may have a comparative advantage (perceived or real) in the production of some trade-able commodity—including production of natural resources scarce or limited elsewhere, or because different regions' size may encourage mass production. As such, trade at market prices between locations can benefit both locations. Retail trade consists of the sale of goods or merchandise from a very fixed location, such as a department store, boutique or kiosk, online or by mail, in small or individual lots for direct consumption or use by the purchaser. Wholesale trade is defined as the sale of goods that are sold as merchandise to retailers, or industrial, commercial, institutional, or other professional business users, or to other wholesalers and related subordinated services.

Long/short - equity is an investment strategy generally associated with hedge funds, and more recently certain progressive traditional asset managers. It involves buying long equities that are expected to increase in value and selling short equities that are expected to decrease in value. This is different from the risk reversal strategies where investors will simultaneously buy a call option and sell a put option to simulate being long in a stock.

Pairs trade or pair trading is a market neutral trading strategy enabling traders to profit from virtually any market conditions: uptrend, downtrend, or sideways movement. This strategy is categorized as a statistical arbitrage and convergence trading strategy. The pair trading was pioneered by Gerry Bamberger and later led by Nunzio Tartaglia’s quantitative group at Morgan Stanley in the 1980s.

Day trading is speculation in securities, specifically buying and selling financial instruments within the same trading day. Strictly, day trading is trading only within a day, such that all positions are closed before the market closes for the trading day.

Stock trader or equity trader or share trader is a person or company involved in trading equity securities. Stock traders may be an agent, hedger, arbitrageur, speculator, stockbroker.

Stock (also capital stock) of a corporation is constituted of the equity stock of its owners. A single share of the stock represents fractional ownership of the corporation in proportion to the total number of shares. In liquidation, the stock represents the residual assets of the company that would be due to stockholders after discharge of all senior claims such as secured and unsecured debt. Stockholders' equity cannot be withdrawn from the company in a way that is intended to be detrimental to the company's creditors.

Stockbroker is a regulated professional individual, usually associated with a brokerage firm or broker-dealer, who buys and sells stocks and other securities for both retail and institutional clients through a stock exchange or over the counter in return for a fee or commission. Stockbrokers are known by numerous professional designations, depending on the license they hold, the type of securities they sell, or the services they provide. In the United States, a stockbroker must pass both the Series 7 and either the Series 63 or the Series 66 exams in order to be properly licensed.

Shares - in financial markets, a share is a unit of account for various investments. It often means the stock of a corporation, but is also used for collective investments such as mutual funds, limited partnerships, and real estate investment trusts.

Finance is a field that deals with the study of investments. It includes the dynamics of assets and liabilities over time under conditions of different degrees of uncertainty and risk. Finance can also be defined as the science of money management. Finance aims to price assets based on their risk level and their expected rate of return. Finance can be broken into three different sub-categories: public finance, corporate finance and personal finance.

Share capital (or capital stock in US English) is the portion of a corporation's equity that has been obtained by the issue of shares in the corporation to a shareholder, usually for cash. In a strict accounting sense, share capital is the nominal value of issued shares (that is, the sum of their par values, as indicated on share certificates). If the allocation price of shares is greater than their par value, e.g. as in a rights issue, the shares are said to be sold at a premium (variously called share premium, additional paid-in capital or paid-in capital in excess of par). Commonly, the share capital is the total of the aforementioned nominal share capital and the premium share capital. Conversely, when shares are issued below par, they are said to be issued at a discount or part-paid.

Shareholder or stockholder is an individual or institution (including a corporation) that legally owns one or more shares of stock in a public or private corporation. Shareholders may be referred to as members of a corporation. Legally, a person is not a shareholder in a corporation until his or her name and other details are entered in the register of shareholders or members

Dividend is a payment made by a corporation to its shareholders, usually as a distribution of profits. When a corporation earns a profit or surplus, the corporation is able to re-invest the profit in the business (called retained earnings) and pay a proportion of the profit as a dividend to shareholders. Distribution to shareholders may be in cash (usually a deposit into a bank account) or, if the corporation has a dividend reinvestment plan, the amount can be paid by the issue of further shares or share repurchase.

Mutual fund is a professionally managed investment fund that pools money from many investors to purchase securities. Mutual funds have advantages and disadvantages compared to direct investing in individual securities. The primary advantages of mutual funds are that they provide a higher level of diversification, they provide liquidity, and they are managed by professional investors. On the negative side, investors in a mutual fund must pay various fees and expenses.