Unfair speed advantage

One way in which high-frequency traders are able to make a profit is simply by being faster than others. This may provide some traders the ability to front-run other investors’ trades.

Magnification of market movements

Trading algorithms may magnify fluctuations in financial markets. For example, a sell off may trigger some of these algorithmic traders to close down positions, thereby magnifying a downward trend. They may also take short positions and continue to increase such positions as long as the market is falling, thereby amplifying the move.

Market manipulation

High-frequency traders may engage in market manipulation. This can be done by spoofing, quote stuffing, wash trading, or painting the tape. We discuss these kinds of market manipulation on the page on suspect trading behavior.

Risk of trading errors

The high speed with which high-frequency traders execute trades also means that if things go wrong, they tend go wrong quickly. Thus, the results may be disastrous if the trades are not as intended. When this happens, it is referred to as an algorithm “going wild’.

Denial-of-service

If trading algorithms send too many orders to a market venue at the same time, it may happen that the exchange is unable to process all of the trades immediately. This may cause the network to become slow or unavailable. It is similar to a denial of service attack that is targeted at websites.

Increased difficulty of policing

As trading is taking place at ever higher speeds, it becomes difficult for regulators to supervise markets. Alternative venues, which are less transparent (e.g. dark pools) also make it more difficult for regulators to investigate suspicious trading behavior.

Unequal access to information

To trade against other high-frequency traders require specialized hardware and software. Thus, it is impossible for smaller investors to compete with high-frequency traders.