The Market Can Remain Irrational Longer Than You Can Remain Solvent

John Maynard Keynes? A. Gary Shilling? Harold R. Evensky? Apocryphal?

Dear Quote Investigator: The gyrations of financial markets can be startling. I am reminded of the following words of wisdom attributed to the economist John Maynard Keynes:

The market can remain irrational longer than you can remain solvent.

Supposedly Keynes said this after he performed a series of highly leveraged trades, and he was humbled by the market. But I have been unable to find any evidence of this maxim before the 1990s. Since you explored another Keynes saying in February I am hoping this one might interest you.

Quote Investigator: Master linguistics researcher Barry Popik and the volunteer editors of WikiQuote have located crucial citations for this quotation [BPRI][WQMK].

The earliest known evidence for this saying appeared in a column by A. Gary Shilling in Forbes magazine in February 1993. Keynes was not mentioned when the aphorism was employed by Shilling [AGSF]:

Above all, in 1993 remember this: Markets can remain irrational a lot longer than you and I can remain solvent.

The journalist Jason Zweig was working at Forbes in 1993, and he believes that he heard the expression “numerous times” before Shilling’s column appeared. He thinks the phrase was in use by the late 1980s [JZFJ]. So Shilling may not be the originator though his name is connected to the earliest and strongest written evidence.

Another remark that has been credited to Keynes for decades may have influenced the attribution of this statement:

There is nothing so disastrous as a rational investment policy in an irrational world.

There is a conceptual overlap between these two quotations, and they share the focal word “irrational.” The reassignment of the statement from Shillings to Keynes may have been facilitated by the existence of this earlier saying. This link leads to the previous blog post exploring this alternative comment.

Here are additional selected citations in chronological order.

In 1995 a message in the Usenet discussion group misc.invest.futures contained a version of the saying. No specific attribution was given within the message [STUI]:

An old trading saying…. that, by the way is very true… “The market can stay irrational a lot longer than you can stay solvent!”…. Thinking about a trade in terms of what the world can and can’t afford can be a dangerous habit.

In 1997 an Associated Press news story quoted A. Gary Shilling using the maxim. The discussion topic was the market and changing interest rates. Shilling did not attribute the adage to anyone else when he spoke [BRGS]:

“Then we may have a clearer idea of the interest rate picture,” said A. Gary Shilling, an award-winning forecaster and president of A. Gary Shilling & Co., based in Springfield. “Given the volatility, you’re really rolling the dice. I’m on the sidelines. The market can remain irrational much longer than I can remain solvent.”

In 1999 the New York Times printed an article that included a comment from Harold R. Evensky, a financial adviser in Florida, in which he credited the maxim to Keynes [NYMK]:

He remains a firm believer in asset allocation, although he said that during the quarter, a sobering market adage from John Maynard Keynes came to mind: Markets can remain irrational longer than you can remain solvent.

In 2002 a writer in the periodical “Investors Chronicle” attached both Keynes and a time frame to the quotation. In this version the word “stay” was used instead of “remain” [ICMK]:

The lessons an old one. As Keynes said in the 1930s: “Markets can stay irrational longer than you can stay solvent.”

In 2007 an article in BusinessWeek credited Keynes with the saying [BWMK]:

The trickiest part of putting your money into a bearish bet is the timing. You can be right that a market or sector is overvalued but wrong on the timing. That’s essentially what economist John Maynard Keynes meant when he said, “The market can stay irrational longer than you can stay solvent.”

In conclusion, this saying appeared in print by the 1990s and was closely associated with the financial analyst A. Gary Shilling. Based on current evidence it is possible that Shilling crafted of this apothegm. The journalist Jason Zweig believes he heard the phrase earlier and thinks it was in use by the late 1980s.

The evidence linking the quote to Keynes is very weak, and may be due to confusion with another saying attributed to Keynes as mentioned above. Thanks for your question.

Update history: Information from Jason Zweig was added to the entry on November 4, 2011.

[BPRI] Barry Popik website, Entry from December 13, 2008: “The market can stay irrational longer than you can stay solvent (Keynes?)” (Accessed on 2011 August 9) link

[WQMK] Wikiquote, Webpage for John Maynard Keynes, Entry for: Markets can remain irrational longer than you can remain solvent. [The handle Cancerward was used by the person who added the 1993 citation for Gary Shilling in Forbes.] (Accessed on 2011 August 9) link

[AGSF] 1993 February 15, Forbes, Scoreboard by A. Gary Shilling, Page 236, Volume 151, Issue 4, Forbes Inc., New York. (ProQuest)

[JZFJ] Personal communication from Jason Zweig of the Wall Street Journal to Garson O’Toole. Email dated August 15, 2011.

[STUI] 1995 September 17, Usenet discussion group, Newsgroup: misc.invest.futures, From: Stewart Taylor, Subject: Re: Ewing’s ideas on Corn. link

[BRGS] 1997 May 1, The Record, Dow Back Up To 7,000 Investors Shrug Off Worrisome Report by Bruce Meyerson, The Associated Press, Section Business, Page B01, Bergen Evening Record Corporation, Bergen County, New Jersey. (ProQuest)

[NYMK] 1999 April 4, New York Times, “Mutual Funds Report: In the Stampede to Big Stocks, Some Managers Are Left Behind” by Carole Gould, Page 3.32, New York. (ProQuest)

[ICMK] 2002 July 25, Investors Chronicle, How to get it right next time, Financial Times Business Limited. (Westlaw Campus Database)

[BWMK] 2007 May 21, BusinessWeek, The Short Sell Made Simple by Lewis Braham, Section Personal Finance, Start Page 98, Quote Page 100, Column 2, Issue 4035, Bloomberg, L.P.  (EBSCO Business Source Premier)