The four most dangerous words for investors are: This time is different. Five Weeks of Financial Turmoil In 1999, technology companies with no earnings or sales were valued at billions of dollars. But this time was different, investors told themselves. The Internet could not be missed at any price.

They were wrong. In 2000 and 2001 technology stocks plunged, erasing trillions of dollars in wealth reports the New York Times.

Now investors have again convinced themselves that this time is different, that the credit crisis will push economies worldwide into the deepest recession since the Depression. Fear runs even deeper today than greed did a decade ago.

But in their panic, investors are ignoring 60 years of history. Since the Depression, governments have become far more aggressive about intervening when credit markets seize up or economies struggle. And those interventions have generally succeeded. The recessions since World War II, while hardly easy, have been far less painful than the Depression.

Now some veteran investors, including G. Kenneth Heebner, a mutual fund manager who has one of the best long-term track records on Wall Street, say that the sell-off has gone much too far and stocks are poised to rally powerfully if the downturn is less severe than investors fear.

“The fact is, there are a lot of tremendous bargains out there,” said Mr. Heebner, who manages about $10 billion in several mutual funds. Indeed, by many measures stocks are as cheap as they have been in the last 25 years.

He pointed to Chesapeake Energy, a natural gas producer that he owns in his CGM Focus mutual fund. In July, Chesapeake traded for $63 a share. On Friday, it fell as low as $11.99.

He says that investors with a stomach for risk and a long time horizon should consider following Warren E. Buffett, who in the last three weeks has invested $8 billion in Goldman Sachs and General Electric.

Read more here: Those with Sense of History May Find It’s Time to Invest