From Michael Hudson –

<em>Take any stock in the United States. The average time in which you hold a stock is–it’s gone up from 20 seconds to 22 seconds in the last year. Most trades are computerized. Most trades are short-term. The average foreign currency investment lasts–it’s up now to 30 seconds, up from 28 seconds last month.

What does that mean for you? If you are an actual human being you are competing, when you make a stock purchase, with a supercomputer, like the ones they use to analyze the weather. That is why the amount of time a stock is held is so low – computer trading.

It’s not a level playing field. A more apt comparison might be a gambling house where the table is rigged to favor the owner almost but not quite always every time. You have to have the occasional lucky winner whose stories will keep the others coming in.

An exaggeration?

Okay, how about this from 2009 –

With all of the scrutiny that high-frequency trading is now under in the media and in Congress, the New York Stock Exchange is probably none too thrilled that the Wall Street Journal has uncovered fresh details of NYSE’s giant new datacenter, which the exchange is building in a former New Jersey quarry. The new datacenter will significantly advance the amount of computer-automated trading that already dominates global markets, housing as it will “several football fields of cutting-edge computing equipment for hedge funds and other firms that engage in high-frequency trading,” according to the WSJ. So if you were recently shocked to learn that an estimated 70 percent of stock trading is just computers trading against one another, get ready for that number to go even higher.

Or this –

Fewer and fewer Wall Street traders are human beings. Instead, they’re computersthat execute trades in milliseconds (a millisecond is one thousandth of a second). A forerunner of today’s robotic trading, computerized program trading, was largely responsible for the stock market crash of October 19, 1987, when the Dow Jones industrial average plunged 22.6%.

This kind of computer trading or should I say, Algorithmic trading, isn’t going away. So if you are a mere mortal, you might find your ability to make money on stock a little constricted by non-human competitors.

James Pilant

Related articles

• Algorithmic Trading is Not High Frequency Trading (minimalj.wordpress.com)
• Regulators May Catch Up With High-Frequency Trading (huffingtonpost.com)
• What does high-frequency trading do to the markets? | Jill Treanor (guardian.co.uk)
• How much does the latency of the data feed play into high frequency trading? (minimalj.wordpress.com)
• Does High-Speed Trading Hurt the Small Investor? (online.wsj.com)
• Computers Blamed (Again) for the Market’s Woes (theatlantic.com)