What is high-frequency trading?
High-frequency trading usually refers to trading done through computer programs that carry out a large number of orders at very fast speeds. These programs use algorithms to analyse the markets and execute orders based on market conditions in a matter of microseconds. In the US, it is estimated that this type of trading accounts for 73% of equity trades.
The purpose of high-frequency trading is to make small, consistent profits, with profits often being smaller than a cent a trade. Because trades take place so quickly, these small sums accumulate to produce significant results at the end of the trading day.
Why is it drawing attention?
One reason is the sheer volume of trading for which high-frequency trading accounts. Also, algorithmic trading has been very successful over the past few years
However, high-frequency trading has also been a source of controversy and has been largely blamed for the May 6, 2010 ‘Flash Crash’ when the Dow Jones plummeted 900 points, or 9%, only to recover those losses in a matter of minutes. In a 14-second period, algorithms caused 27,000 contracts of the S&P 500 E-mini futures contracts to change hands yet, in net terms, only 200 of those contracts were actually bought. Although the trades only netted out to small amounts, the huge amount of notional value created extreme market instability.
Are there benefits to high-frequency trading?
Some sources claim that algorithmic trading improves market liquidity, which not only means there is an ever-ready flow of assets available when traders need them, but also lowers the costs of trading.
A 2010 Journal of Finance study also argued that high-frequency trading also increased the informativeness of market quotes as well as improving the linkage between markets.
The implications of high-frequency trading
Whether you are in the ‘for’ or ‘against’ group, the growing use of high-frequency trading has and will continue to impact the markets.
First, it increases market volatility, meaning that an increasing number of shares are traded for reasons that have nothing to do with a company’s performance. The speed at which high-frequency trades can take place creates a misalignment between share prices and fundamentals, as an asset cannot meaningfully change value in a micro-second.
Second, high-frequency trading is shortening the amount of time investors hold a stock. At the end of WWII, the average American share was held for an average of four years. By 2000, it had dropped to eight months. It is now less than two months and falling. This suggests that the alignment between investors and their companies, which create value together over a number of years, is breaking down.
This has resulted in a rupture between the performance of shares and the performance of the underlying companies, and this shorter-term focus is likely to switch market emphasis from fundamentals to sentiment.