Half the Market

I’ve seen at least four Wall Street Journal stories in May alone about a quiescent VIX.

The CBOE’s volatility index derived from options pricing on the S&P 500 hit a low Monday last seen in Dec 1993, the WSJ said (subscription required). It moved lower still yesterday, 9.58 intraday.

Implicit in the storyline is a bull market, since one roared from 1993 to the bursting of the dot-com bubble. But the conclusion violates the Law of Small Numbers, the human propensity to assign undue value to insignificant data sets.  As proof, the VIX was a hair’s breadth from record low in Jan 2007.

Remember that? Lehman, little did we know, was failing. The financial crisis thereafter manifested in markets like a Hollywood blockbuster action movie where the hero outruns the explosion as the structure dissolves in showering computer-generated fantasia.

Since we can make equal bull or bear cases with the same data, it supports neither.

Aside: The investor-relations profession has a notorious proclivity toward the Law of Small Numbers. Stock’s down 3%, so we call somebody to learn why. You’re chasing the exception. Track instead the central tendency in the whole data set so you can see what changed before the stock fell 3%.

And assigning rational motivation to the VIX defies the data.  Less than 20% of daily market volume comes from rational thought. The rest is tracking the mean, arbitraging spreads back to the mean, or hedging departures from the mean.

Where everything is average, volatility vanishes. Thus a dead VIX fits. It offers little predictive value (save higher volatility always follows very low) and simply points to low spreads.

The reason is market structure. Passive investment tracks benchmarks and so seeks the mean – average price. Arbitragers look for departures from the mean to trade for profit. The market is riven with arbitrage so few mean-divergences survive to the close. But boy is there opportunity. You’ll see soon.

Meanwhile, those managing risk offload exposure to someone else, which produces equal and offsetting trading – which reinforces the mean.

And here’s a shocker. We track daily share-borrowing – shorting – as a percentage of total trading volume. Short shares are 48.1% of volume, which means long trades are 51.9%. In other words, nearly half the market is short.

Locked markets, or trades where the bid to buy equals the asking price to sell, are prohibited, so there will always be a spread, a dab of volatility. Arbitragers are almost guaranteed gains by being long and short everywhere.

We also measure intraday volatility, the spread between average intraday high and low prices. It’s 2.5% – astonishing arbitrage fodder.

For perspective, the S&P 500 rose 0.5% the last ten sessions. That means stocks are 400% more volatile every day than the ten-day change in closing prices.

Arbitragers are making tremendous gains by consuming intraday volatility.

It may be that Exchange-Traded Fund (ETF) market-makers are responsible. It explains why ETF costs are so low: Arbitrage gains are additive.

And ETF sponsors can rent out liquidity, shares accounting for the 48% of trading that’s borrowed – boosting returns. There’s support in the data. We track passive-investment patterns and correlate them to short volume, and there’s agreement.

ETF market-makers have four arbitrage opportunities: a) ETF net asset value versus ETF price; b) ETF versus underlying index; c) ETF price versus prices of components of the index; d) ETF price versus options and futures on components and the index.

By the close, ETFs and indexes want to peg the measure so divergences converge at average.

It’s a circumstantial case. But evidence piles up that ETFs are consuming spreads while simultaneously driving stock-prices and deflating the VIX.

What’s the risk?  Mortgage-backed securities did the same thing to real estate.  There was a finite asset, homes. With cheap mortgages, lots of money wanted exposure. So home loans were securitized – replicated – to expand demand, delivering great returns to those selling them. It worked till home prices stopped rising. Then replicated value evaporated. Half the market.

There are less than 3,600 US public companies when ETFs, multiple share classes and closed-end funds are removed. Low rates have created high demand. To expand access, ETFs replicate exposure, and are booming. It works so long as stocks rise.

When that stops at some sure point, extrapolated value will be marked to zero. Half the market.  Won’t arbitragers save the day? Not if volatility jumps as average prices plunge.