Algorithmic Trading

Algorithmic trading is a process for executing orders utilizing automated and pre-programmed trading instructions to account for variables such as price, timing and volume. An algorithm is a set of directions for solving a problem. Computer algorithms send small portions of the full order to the market over time.

Algorithmic trading makes use of complex formulas, combined with mathematical models and human oversight, to make decisions to buy or sell financial securities on an exchange. Algorithmic traders often make use of high-frequency trading technology, which can enable a firm to make tens of thousands of trades per second. Algorithmic trading can be used in a wide variety of situations including order execution, arbitrage, and trend trading strategies.

The use of algorithms in trading increased after computerized trading systems were introduced in American financial markets during the 1970s. In 1976, the New York Stock Exchange introduced the Designated Order Turnaround (DOT) system for routing orders from traders to specialists on the exchange floor. In the following decades, exchanges enhanced their abilities to accept electronic trading, and by 2009, upwards of 60 percent of all trades in the U.S. were executed by computers.

Author Michael Lewis brought high-frequency, algorithmic trading to the public’s attention when he published the best-selling book Flash Boys, which documented the lives of Wall Street traders and entrepreneurs who helped build the companies that came to define the structure of electronic trading in America. His book argued that these companies were engaged in an arms race to build ever faster computers, which could communicate with exchanges ever more quickly, to gain advantage on competitors with speed, using order types which benefited them to the detriment of average investors.

In recent years, the practice of do-it-yourself algorithmic trading has become widespread. Hedge funds like Quantopian, for instance, crowd source algorithms from amateur programmers who compete to win commissions for writing the most profitable code. The practice has been made possible by the spread of high-speed internet and the development of ever-faster computers at relatively cheap prices. Platforms like Quantiacs have sprung up in order to serve day traders who wish to try their hand at algorithmic trading.

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