By Peter Gomber, Björn Arndt, Marco Lutat, Tim Uhle

Executive Summary

High-frequency trading (HFT) has recently drawn massive public attention fuelled by the U.S. May 6, 2010 flash crash and the tremendous increases in trading volumes of HFT strategies. Indisputably, HFT is an important factor in markets that are driven by sophisticated technology on all layers of the trading value chain. However, discussions on this topic often lack sufficient and precise information. A remarkable gap between the results of academic research on HFT and its perceived impact on markets in the public, media and regulatory discussions can be observed.

The research at hand aims to provide up-to-date background information on HFT. This includes definitions, drivers, strategies, academic research and current regulatory discussions. It analyzes HFT and thus contributes to the ongoing discussions by evaluating certain proposed regulatory measures, trying to offer new perspectives and deliver solution proposals. Our main results are:

HFT is a technical means to implement established trading strategies. HFT is not a trading strategy as such but applies the latest technological advances in market access, market data access and order routing to maximize the returns of established trading strategies. Therefore, the assessment and the regulatory discussion about HFT should focus on underlying strategies rather than on HFT as such.

HFT is a natural evolution of the securities markets instead of a completely new phenomenon. There is a clear evolutionary process in the adoption of new technologies triggered by competition, innovation and regulation. Like all other technologies, algorithmic trading (AT) and HFT enable sophisticated market participants to achieve legitimate rewards on their investments – especially in technology – and compensation for their market, counterparty and operational risk exposures.

A lot of problems related to HFT are rooted in the U.S. market structure. The flash crash and the discussions on flash orders relate to the U.S. equity markets and the NMS. In Europe, where a more flexible best execution regime is implemented and a share-by-share volatility safeguard regime has been in place for two decades, no market quality problems related to HFT have been documented so far. Therefore, a European approach to the subject matter is required and Europe should be cautious in addressing and fixing a problem that exists in a different market structure thereby creating risks for market efficiency and market quality.

The majority of HFT based strategies contributes to market liquidity (market making strategies) or to price discovery and market efficiency (arbitrage strategies). Preventing these strategies by inadequate regulation or by impairing underlying business models through excessive burdens may trigger counterproductive and unforeseen effects to market quality. However, any abusive strategies against market integrity must be effectively combated by supervisory authorities.

Academic literature mostly shows positive effects of HFT based strategies on market quality. The majority of papers, focusing on HFT, do not find evidence for negative effects of HFT on market quality. On the contrary, the majority argues that HFT generally contributes to market quality and price formation and finds positive effects on liquidity and short term volatility. Only one paper critically points out that under certain circumstances HFT might increase an adverse selection problem and in case of the flash crash one study documents that HFT exacerbated volatility. As empirical research is restricted by a lack of accessible and reliable data, further research is highly desirable.

In contrast to internalization or dark pool trading, HFT market making strategies face relevant adverse selection costs as they are providing liquidity on lit markets without knowing their counterparties. In internalization systems or dark venues in the OTC space, banks and brokers know the identity of their counterparty and are able to ?cream skim? uninformed order flow. In contrast, HFTs on lit markets are not informed on the toxicity of
their counterparts and face the traditional adverse selection problems of market makers.

Any assessment of HFT based strategies has to take a functional rather than an institutional approach. HFT is applied by different groups of market players from investment banks to specialized boutiques. Any regulatory approach focusing on specialized players alone risks (i) to undermine a level playing field and (ii) exclude a relevant part of HFT strategies.

The high penetration of HFT based strategies underscores the dependency of players in today’s financial markets on reliable and thoroughly supervised technology. Therefore, (i) entities running HFT strategies need to be able to log and record algorithms‘ input and output parameters for supervisory investigations and back-testing, (ii) markets have to be able to handle peak volumes and have to be capable of protecting themselves
against technical failures in members‘ algorithms, (iii) regulators need a full picture of potential systemic risks triggered by HFT and require people with specific skills as well as regulatory tools to assess trading algorithms and their functionality.

Any regulatory interventions in Europe should try to preserve the benefits of HFT while mitigating the risks as far as possible by assuring that (i) a diversity of trading strategies prevails and that artificial systemic risks are prevented, (ii) economic rationale rather than obligations drive the willingness of traders to act as liquidity providers, (iii) colocation and proximity services are implemented on a level playing field, (iv) instead of
market making obligations or minimum quote lifetimes, the focus is on the alignment of volatility safeguards among European trading venues that reflect the HFT reality and ensure that all investors are able to adequately react in times of market stress.

The market relevance of HFT requires supervision but also transparency and open communication to assure confidence and trust in securities markets. Given the public sensitivity to innovations in the financial sector after the crisis, it is the responsibility of entities applying HFT to proactively communicate on their internal safeguards and risk management mechanisms. HFT entities act in their own interest by contributing to an environment where objectivity rather than perception leads the debate: They have to draw attention to the fact that they are an evolution of securities markets, supply liquidity and contribute to price discovery for the benefit of markets.