The current discourse on high-frequency trading is often challenged by a distortion of definitions. Journalists, politicians and industry analysts bend or stretch definitions to meet their various (and often conflicting) objectives. For example, flash orders and high-frequency trading have been improperly used as equivalent terms. Front-running has been invoked when "liquidity detection" would be more accurate. While there is room for a legitimate debate over the scope, size and impact of high-frequency trading, the industry must first agree to terms. Below, TABB Group outlines a few principles to which it adheres when discussing this controversial subject:
HFT refers to fully automated trading strategies (in equities, derivatives or currencies) that seek to benefit from market liquidity imbalances or other short-term pricing inefficiencies. These opportunities could last from milliseconds to minutes and possibly hours. While these strategies can be employed overnight, the majority of HFT strategies attempt to be market-neutral or closed out by the end of each day.
The kinds of strategies that fall under HFT include electronic market making, liquidity detection, cross-asset arbitrage, short-term statistical arbitrage and volatility arbitrage. The most prevalent equity HFT strategy is electronic market making, in which firms attempt to profit from intraday imbalances in the supply and demand for liquidity. Not all market making is high-frequency (though almost all of it is), and not all high-frequency trading is market making, but market-making strategies profit by intelligently managing the risk caused by inconsistencies between buyers and sellers.
Perhaps the most controversial and least understood aspect of high-frequency trading falls under the category of liquidity detection. While classic market makers attempt to capture spread by aggressively quoting at the bid and the ask of a number of stocks, a liquidity detector uses techniques to sniff out large orders of blocks being sliced and diced (usually by an algorithm) that a high-frequency trader believes it can outsmart.
Who Does It?
Although HFT makes up a large portion of total trading activity, a relatively small number of firms are responsible for its volume. Three types of firms build their strategies around HFT: proprietary trading firms (virtual market makers), the largest hedge funds and investment banks' proprietary trading desks. While each of these institutions has a unique position in the industry, their common ground is their mandate to achieve uncorrelated and high returns.
Approximately one-half of liquidity provisioning these days comes from traditional market makers or large broker-dealers. The remainder originates from low-profile (though this is now changing) high-frequency trading firms -- the proprietary (prop) trading shops -- that few other than the industry intimates have ever heard of. Prop shops have been around for many years, earning their profits by risking their own capital. They originated either from groups formerly within broker-dealers or independent firms that have the knowledge, skills and technology to fully automate the trading process; or from screen-based day-trading shops that began automating their strategies in the late 1990s/early 2000s. These prop shops virtually automated the market-making function by leveraging inexpensive computing cycles, low-latency infrastructures and fully automated trading strategies.
Most HFT prop shops choose to keep their identities and intentions secretive, operating under the radar in the hope of improving their chance to profit. Through a thorough examination of Web sites and other public information, TABB Group has found that while the vast majority of these firms trade U.S. equities, the firms are quick to apply their strategies to the entire array of asset classes (see chart).
Investment banks have always traded for their own accounts. Their prop desks typically operate from a distinct legal entity -- separate from the entity that handles customer orders -- within the investment bank; the bank risks its own capital by deploying trading strategies designed to maximize profit. Two divisions within investment banks that deploy HFT are automated market making and proprietary desks. Market makers are registered with the SEC, using traditional trading strategies to facilitate liquidity in the market. Prop desks implement a variety of arbitrage strategies, some of which are high-frequency (though certainly not exclusively high-frequency).