High-Frequency Trading (HFT)
In very broad terms, high-frequency trading (also known as HFT) refers to the buying and selling of stocks at extremely fast speeds with the help of powerful computers. Using complex algorithms, these computers can scan dozens of public and private marketplaces simultaneously, execute millions of orders a second, and alter strategies in a matter of milliseconds. In the U.S., high-frequency trading firms represent 2.0% of the approximately 20,000 firms operating today, but account for 73.0% of all equity trading volume.
As an example, let's assume that a buyer wants to buy 100,000 shares of INTC. The market price of an INTC share is $26.10, but the buyer's limit price is $26.40. In other words, the buyer is willing to pay up to $26.40 for each share of INTC or $0.30 more than its current price.
Via flash orders from NASDAQ, high-frequency trading firms get a peek at these orders for 30 milliseconds before they are shown to everyone else. Having detected a demand for INTC shares, the computers at these firms then start issuing small immediate or cancel (IOC) orders at specific levels above the current price of INTC shares. If the first sell order at $26.15 is accepted by the buyer, another sell order at $26.20 is issued, and so on.
This continues until a sell order at $26.45 is issued. Because the buyer's limit price is $26.40, the sell order at $26.45 is rejected. At this stage, the firms' computers flood the buyer with sell orders at $26.39, causing most of the company's order of 100,000 INTC shares to be filled at $0.29 cents above market price.
Under normal circumstances, a buyer would see the sell order at $26.15 and might subsequently drop the limit price on his/her order. However, high-frequency trading computers are so fast that unless the buyer owned comparable machines, he/she would have no chance to do this.
Firms that engage in high-frequency trading include proprietary trading desks at a small number of major investment banks (like Goldman Sachs and Merrill Lynch), hundreds of the most secretive proprietary trading groups (like Wolverine, Renaissance Technologies, IMC and Getco) and less than 100 of the most sophisticated hedge funds. As a rule, they tend to be secretive, stealthy, smart and relatively unknown.
High-frequency trading is characterized by a high turnover of capital. The positions have very short holding times in computer-driven responses to market situations. Typically high frequency trading applies to multiple trades each day, gaining small returns per trade, with very limited, if any, positions carried overnight. Overnight positions are not considered for high speed trading because with the current volatility in the markets, which extend most of the trading activity over the to 24-hour, they are particularly risky. Moreover, overnight positions taken out on margin have to be paid for at the interest rate referred to as an overnight carry rate decreasing the profitability of of this type of operations.
High-frequency trading strategies are highly dependent on ultra-low latency. To realize any real benefit from implementing these strategies, a firm must have a real-time, colocated, high-frequency trading platform where data is collected, and orders are created, routed and executed in sub-millisecond times.
Ultra-Low Latency Direct Market Access. For HFT strategies speed of execution is key. DMA or DSA(algo) are means of executing trading flow on a selected venue by almost bypassing the brokers discretionary methods. For the lack of interaction with the broker this is sometimes refered to as no-touch. DMA flow passes directly through the DMA market gateway and onto the venue while passing though strict risk checking and position keeping algorithms. It is at this point the brokers may monitor the behaviour of their DMA clients. For the purposes of HFT trading, the DMA must not delay orders by more than a millisecond with a few technology firms able to achieve round trip times in the microseconds. With the ability to co-locate the HFT traders blackboxes with the DMA next to a venue's matching engine, Ultra-low latency can be achieved.
Since many high-frequency trading strategies require transactions in more than one asset class and across multiple exchanges, appropriate infrastructure is required to facilitate long-haul connectivity between different data centers.
The competitive advantage of a high-frequency trading strategy dilutes over time. Although a firm's high-level trading strategy may remain consistent over time, its micro-level strategies are constantly altered for two important reasons. Firstly, because high-frequency trading depends on extremely precise market interactions and security correlations, traders need to regularly adjust code to reflect subtle changes in the dynamic market. Secondly, competitive intelligence is so good across rival trading firms that each is exposed to the increasing susceptibility of their strategies being reverse-engineered, turning their most profitable ideas into their most risky.
On 21 July 2009, in the wake of Sergey Aleynikov's theft of top secret code for Goldman’s high-frequency trading platform, Matthew Goldstein of Reuters called for "securities regulators to start taking a [closer] look at so-called high frequency trading and the impact that this speed-of-light trading strategy [was] having on the markets." He argued that if "a computer code [was] valuable enough for someone to steal, and critical enough for a Wall Street firm to go to federal authorities to protect, one would think that regulators would want to know why it is so important."
On 24 July 2009, Karl Denninger of The Market Ticker accused high-frequency traders of "intentionally probing the market with tiny orders [...] to gain an illegal view into the other side's willingness to pay. This pattern of offering [sell orders at different levels] was intended to do one and only one thing; manipulate the market by discovering [...] a hidden piece of information - the other side's limit price!" He went on to argue that "the presence of these programs [would] guarantee huge profits to the banks running them" and that "retail buyers would get screwed as the market [moved] much faster to the upside than it otherwise would."
On 24 July 2009, Senator Charles E. Schumer, the New York Democrat who is chairman of the Senate rules and administration committee, wrote in a letter to Mary Shapiro, Chairman of the SEC, that the technique known as flash orders "gives high-frequency traders using lightning-fast computers an unfair advantage." He requested the SEC to "act to prohibit the use of so-called 'flash orders' in connection with optional display periods currently permitted by Direct Edge's Expedited Liquidity Program, NASDAQ's Flash Order Program and BATS Bolt Optional Liquidity Program." Mr. Schumer wrote that he intended to introduce legislation barring the technique if the agency failed to curb this practice.
On 17 September 2009, the U.S. Securities and Exchange Commission proposed banning flash orders after lawmakers said the practice may give hedge funds an advantage over other investors. SEC commissioners unanimously voted to seek public comment on a rule barring exchanges and trading platforms from giving clients access to information about stock orders a fraction of a second before the market. The proposal requires a second vote at a later public meeting to become binding. Nasdaq OMX Group Inc. and Bats Global Markets voluntarily dropped flash orders in August after the practice drew scrutiny from Congress and the SEC. NYSE Euronext, operator of the world’s largest exchange, is the only exchange that didn’t offer flash orders. The decision puts pressure on Direct Edge Holdings LLC, the only equity network still allowing the practice.
The Real Power Behind Predatory High Frequency Trading]