Religion, The Stock Market, and the Search for Meaning

People want to understand phenomena.  We want explanations for what happens. Journalists, especially TV and radio journalists, want explanations that can be summarized in 1-2 sentences in a sound bite.  Randomness is pretty scary.  And anything that’s too complex to understand easily looks a lot like randomness.

So what triggered this little nugget of metaphysical social observation in an economics blog?  Reporting on the stock market!  Everyday we (those of us who read, listen or watch the news) are treated to not only reports of what the major stock market averages have done that day, but we’re always given a simple and easy explanation.  Just look at today in the NYTimes.  I’m not trying to pick on The Times, it was just the first thing showing on Google Finance as I wrote this – any source, any time and you’ll get similar simplistic explanations.

The move announced by central bankers on Wednesday to contain the European debt crisis led to euphoria in global stock markets…

Krugman posted this evening that he didn’t understand it.  But he approached it from the standpoint of “does this action by ECB make economic sense that should improve stock prices?’.  I think he’s right that it doesn’t make sense, but I think he misses a bigger point.  It’s foolish to try to attribute the movements of stock market averages on any given day to the any particular sentiment of investors or any particular logic of rational investors.

The markets are huge.  We’re talking hundreds of billions and trillions of dollars in trades. Daily volume is in the billions of trades everyday. It’s complex, folks. The reasons these trades happen and why they happened at the prices they did are really, really complex.   It’s kind of like ancient peoples trying to understand the stars and without even a telescope or any calculus! Unfortunately, like them, we want simple explanations.  So we invent them.  And like ancient peoples we make sure our explanations support and reinforce whatever religious or superstitious beliefs we have.  [readers are advised not to try to decide what my spiritual beliefs are based on that sentence – it’s complicated].

There is a belief that supports much of this daily “this is what the market did and why” reporting. It’s actually based on the theory that markets are rational and “efficient”.  There’s an economic theory that holds that prices in financial markets accurately reflect the current state of all known information and news regarding the future flow of earnings and profits from firms.  It’s demonstrably false, but it has quite a following among neoclassical economists.  It cannot be proven and evidence exists to contradict the hypothesis (see Quiggin’s Zombie Economics), yet it’s taken as article of faith among many, many economists.  So much so that some non-believing economists have begun to refer to neoclassical economics as theo-classical.

The whole idea that there’s a single sentiment or key piece of news that drives the stock market each day is made even more absurd when we realize that most trading isn’t even being done by humans!  The significant majority of all trades are done by computers based on algorithms such as “buy this if the price has moved x in the last y seconds”.  Even more of the trading is done by casino-oriented short-term trading by large banks and hedge funds who are only trying to figure out what they think the other traders are going to do a few seconds before they do it. (also known as Keynes’ beauty contest).

Markets are the collective, sum judgement of lots of complex decisions.  Even if all the individual decisions were rational, there’s still no reason to believe the aggregate outcome can be represented as the decision of some hypothetical rational being.  So next time you hear or read some talking head pontificate that “the markets are saying…..”, just remember there’s little difference between that modern commentator and some ancient priest in long gown claiming that “the gods are saying….”

RIP: Efficient Markets Hypothesis – 70% of stock trades last 11 seconds or less

One of the economic theories that dominated a mainstream economic theory during the last few decades is Efficient Markets Hypothesis.  Essentially, an important part of the concept is that asset prices, such as stock prices on the stock exchange, accurately reflect all available information about the future earnings of the firm.  Further, it implies that stock price movements reflect changes in these perceptions.  There’s a lot wrong with the theory as is explained quite well in Zombie Economics by John Quiggin.  But let’s add this little bit from Washington’s blog and Naked Capitalism.

Washington’s Blog

The Fourteenth Banker writes today:

In the stock market, program trading dominates volume. I heard recently that 70% of trade positions are held for an average of 11 seconds.

He’s correct.

As the New York Times dealbook noted in May:

These are short-term bets. Very short. The founder of Tradebot, in Kansas City, Mo., told students in 2008 that his firm typically held stocks for 11 seconds. Tradebot, one of the biggest high-frequency traders around, had not had a losing day in four years, he said

Similarly, FT’s Martin Wheatley pointed out last month:

I know of one HFT firm operated out of the west coast of the US that boasts its average holding period for US equities is 11 seconds

And market analyst Peter Cohan writes at AOL’s Daily Finance:

70% of trading volume on the major exchanges is conducted by high-frequency traders who hold a stock for an average of 11 seconds.

The fact that the vast majority of stock market trades are held for 11 seconds shows that the stock market is not a real market with real traders governed by the law of supply and demand, and with no real price discovery.