High Frequency Trading Is Destroying Liquidity

  • Posted on: August 9, 2011

Enough Already!

On Friday, Aug 5, 2011, we processed 1 trillion bytes of data for all U.S. equities, options, futures, and indexes. This is insane. A year ago, when we processed half of that, we thought it was madness. A year before that, when it was 250 billion bytes, we thought the same. There is no new beneficial information in this monstrous pile of data compared to 3 years ago. It is noise, subterfuge, manipulation. The root of all that is wrong with today’s markets.

HFT is sucking the life blood out of the markets: liquidity. It is almost comical, because this is what they claim to supply. No one with any sense wants to post a bid or ask, because they know it will only get hit when it’s at their disadvantage. Some give in, and join the arms race. Others leave.

Take the electronic S&P 500 futures contract, known as the emini, for example. This is, or used to be, a very liquid market. The cumulative size in the 10 levels in the depth of book was often 20,000 contracts on each side. That means a trader could buy or sell 20,000 contracts “instantly” and only move the market 10 ticks or price levels. Even during the flash crash, before the CME halt, when hot potatoes were flying everywhere, the depth would still accommodate an instant sale of 2,000 contracts.

What used to be the most liquid and active contract in the world, which served as a proxy for the true price of the US stock market for decades, is getting strangled by the speed of light, a weapon wielded by HFT.

Not anymore. On Friday, 2,000 contracts would have sliced right through the entire book. Not during a quiet period, or before a news event. Pretty much any minute of trading that day after the 9:54 slide. And it wasn’t just Friday, the trend in the depth of book size has been declining rapidly over the last few week. What used to be the most liquid and active contract in the world, which served as a proxy for the true price of the US stock market for decades, is getting strangled by the speed of light, a weapon wielded by HFT.

Without going into detail at this time, we think we know one cause of the drop in liquidity. A certain HFT algorithm that we affectionately refer to as The Disruptor, will sell (or buy) enough contracts to cause a market disruption. At the same exact time, this algo softens up the market in ETFs such as SPY, IWM, QQQ, DIA and other market index symbols and options on these symbols. When the disruptor strikes, many professional arbitrageurs who had placed their bids and offers in the emini suddenly find themselves long or short, and when they go to hedge with ETFs or options, find that market soft and sloppy and get poor fills. Naturally, many of these arbitrageurs realize the strategy no longer works, so they no longer post their bids and offers in the emini. Other HFT algos teach the same lesson — bids or offers resting in the book will only become liabilities to those who can’t compete on speed.

In summary, HFT algos reduce the value of resting orders and increase the value of how fast orders can be placed and cancelled. This results in the illusion of liquidity. We can’t understand why this is allowed to continue, because at the core, it is pure manipulation.