Alan Greenspan, the former Federal Reserve chairman behind Wall Street’s most famous bubble warning, did not call the top.
When Greenspan warned about “irrational exuberance” in December 1996, the Nasdaq Composite (^IXIC) had already surged from a fresh breakout. It would keep running for more than three years.
That timing is relevant again as investors debate whether the AI-led Nasdaq rally has gone too far, too fast.
Greenspan, who chaired the Fed from 1987 to 2006 and died Monday at the age of 100, cemented his place in market history with a phrase that became inseparable from the dot-com boom. But the actual warning was more cautious than the shorthand suggests.
Greenspan framed it as a question: “How do we know when irrational exuberance has unduly escalated asset values, which then become subject to unexpected and prolonged contractions?”
The Fed chief was not declaring that stocks had peaked. He was asking how central bankers should think about asset prices before the fallout reached the real economy.
What happened after Greenspan warned of “irrational exuberance” in 1996. Both lines start when the Nasdaq reclaimed record highs: March 14, 1995, and Feb. 29, 2024. The dot-com line continues to its March 2000 peak. ยท Yahoo Finance analysis of AlphaSpace data
Both lines in the chart begin when the Nasdaq reclaimed record highs after prolonged downturns: March 14, 1995, for the dot-com era and Feb. 29, 2024, for the AI era. The modern line runs through Monday, June 22. The dot-com line keeps going to its peak on March 10, 2000.
At the point that corresponds to today, the AI-era Nasdaq is up about 65% from its breakout. The dot-com Nasdaq was up about 79% at the same point.
Then came the part investors remember: From that historical point, the Nasdaq rallied another 249% before peaking in March 2000.
Greenspan’s famous phrase was less a sell signal than a question about when excess becomes dangerous.
For the dot-com Nasdaq, the answer was still more than three years away.
Jared Blikre is the global markets and data editor for Yahoo Finance. Follow him on X at @SPYJared or email him at jaredblikre@yahooinc.com.
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