Be worried if the trading day starts like this.

Photographer: Scott Olson/Getty Images

Being Late to a Trade May Not Be So Bad

Barry Ritholtz is a Bloomberg View columnist. He founded Ritholtz Wealth Management and was chief executive and director of equity research at FusionIQ, a quantitative research firm. He blogs at the Big Picture and is the author of “Bailout Nation: How Greed and Easy Money Corrupted Wall Street and Shook the World Economy.”
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One of the articles in my morning reads yesterday was an intriguing story by the Wall Street Journal with the headline, "Why Morning Is the Worst Time to Trade Stocks."

It reminded me of someone who in my early days in the 1990s was very formative in my philosophy of markets and investing: Don Hays. (See this 2001 Barron’s interview to get a flavor of his views). He was a big proponent of the Smart Money Index (SMI) -- first described by Lynn Elgert in the Feb. 22, 1988 issue of Barron’s -- and is the person who is most often credited with popularizing it. We will get to the SMI shortly.

Several things made Hays a fascinating mentor to a green trader like me. First, he was a rocket scientist. That isn't an exaggeration -- Hays was a former aerospace engineer, and was part of the team that developed the Saturn rocket for NASA.

Second, Hays used what seemed to a younger (and thinner) me to be a very rational approach to markets. His philosophy was quantitative, evidence-based and data-driven. The framework he worked off of used four factors: trend, investor psychology, monetary conditions and valuation. It all seemed very reasonable, especially when compared with the touchy-feely approaches that were so popular elsewhere, especially among the punditocracy.

Last, it didn’t hurt that he was pretty much the most accurate market strategist in the 1990s. He successfully navigated the slowdown in 1994 when the Federal Reserve raised rates and the weakness in 1997-98 amid the collapse of Long-Term Capital Management. Hays stayed bullish until sounding a prescient warning in early 2000. He lost his touch in the 2000s, but let’s hold off on that story for another time.

Nevertheless, the Wall Street Journal article speaks to Hays' fascination with the SMI.

The SMI is calculated by comparing the trading action of the Dow Jones Industrial Average during the first 30 minutes of the day versus the last hour before markets close. You can find updated versions of the index at Sentiment Trader

I am unconvinced this still has much applicability in the modern era, but it is a good jumping off point for a broader discussion.

The first half hour of stock-market trading has been described as “dumb money.” It can be emotionally driven buying and selling, based on news flow or overseas action from the night before. Just think about it: How smart is trading based on what happened while you were sleeping? In a rising market, it engenders a sense of chasing market moves higher; as we have seen, those gains can and do often fade. In a down market, it leads to selling into weakness.

The flip side to this approach is end-of-day buying. It tends to be more pragmatic then emotional. It is often institutional in nature. Rather than making a decision driven by fleeting sentiment, institutions tend toward an investment posture that is executed according to a plan. The buying, often measured by metrics such as volume-weighted average price, can also be a ploy traders use to demonstrate to portfolio managers that they are getting the “best price.”

No two markets or periods in financial history are identical. The current era has seen a major shift in market structure, and perhaps a chastened public that's less inclined to dabble. Maybe the SMI has been rendered obsolete, a victim of high-frequency trading, the declining importance of the Dow as an index and the shift toward exchange-traded funds. Regardless, it might pay dividends to pay attention to early and late widening of bid-ask spreads and understand what's driving them. Pardon my cliche, but I wouldn't necessarily say that the early bird gets the worm, though the second mouse does get the cheese.

This column does not necessarily reflect the opinion of the editorial board or Bloomberg LP and its owners.

To contact the author of this story:
Barry L Ritholtz at britholtz3@bloomberg.net

To contact the editor responsible for this story:
James Greiff at jgreiff@bloomberg.net