Over eight years ago I published an article about the S&P 500 and its volume data. With apologies to Jimi Hendrix and Voodoo Chile, this is my slight return to the subject. We have just 7 months left in the 2010s, but we are close enough for an update.

Sources: Yahoo! Finance; AIM Consulting, LLC

Contact me so that I can help your investment firm. I make my living as a consultant, not as a writer. My job is to help you and your investment team get better.

The Take-Aways…

The busiest trading day ever for the S&P 500 remains 10 October 2008, when a phenomenal 11,456,230,400 shares changed hands. Amazingly, this volume was almost double the trading volume for the entire decade of the 1950s. Furthermore, that total was 210% more than the average daily trading volume of the 2010s. Other data I have published elsewhere demonstrates that approximately 0.35% of shares outstanding trade each day in the United States. Said another way, almost 1 in 100 shares outstanding traded that October day in 2008.

The slowest trading day ever for the S&P 500 was Christmas Eve day 1951, when a paltry 680,000 were bought and sold. Clearly, unless a meteor takes out the earth, or there are massive share buybacks, or something else extraordinary, this will always remain the slowest trading day of all time. Drop that piece of trivia into your next Zoom cocktail hour.

As you can see in the table above, the total number of shares traded per decade for the S&P 500 has grown tremendously, from total shares of 5.78 billion traded for the entire 1950s to 8.7 trillion so far traded in the 2010s. When I last published S&P 500 volume data the growth in shares traded was enormous each decade, and always in the low- to mid-triple digits. But growth in volume traded per day has grown just 23.3% in the 2010s.

The average shares traded per day for the S&P 500 has grown from 2.3 million to 3.7 billion. When I published the first iteration of this data in 2012 the average daily shares traded was 4.1 billion. The last eight years have seen a tremendous slow down in the shares traded per day pace. Any thoughts as to what caused the slow down?

Correlation between trading volumes and prices peaked in the decade of the 1990s at 92.8%. This means that as trading volumes went up from the 1950s through the end of the year 2000, so did prices. The total trend for the entire time series remains 79.8%. But since the 1990s, the correlation between S&P 500 trading volume and prices have trended to zero. In the 00s the correlation was -7.3% and now stands out a paltry -1.8%. Interesting stuff. I like to pride myself on my interpretations of data, but I admit I do not know how to interpret this result. Any thoughts?

Last, and perhaps most fascinating is that in the entire trading history of the S&P 500, 90.9% of all shares traded ever has occurred in the last (almost) 20 years. Wow!

Contact me so that I can help your investment firm. I make my living as a consultant, not as a writer. My job is to help you and your investment team get better.