"Remember in 1999 the S&P  went to a 30 PE [price-to-earnings ratio]. Next year PE is now like 16," Tepper wrote.
The S&P 500 rose 19 percent in 1999, peaking in 2000 and sliding to a bottom in 2002.
The year 1999 was also associated with the tech bubble, as the Nasdaq Composite index shot up like a rocket, only to fall off a cliff in early 2000 and follow the broader market lower.
The recent Russian currency crisis has also recalled memories of a similar situation in 1998 that forced Russia to default on its debt.
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In a rough year for active managers, Tepper was back in positive territory for 2014, with a 4.5 percent November gain in his Palomino Fund, according to Institutional Investor's Alpha. The fund lost 6.3 percent during the October swoon. No information was available for December.
Appaloosa, which manages about $20 billion, plans to return 10 to 20 percent of investor assets by the end of 2014, Alpha reported, the fourth straight year he's returning money to clients.
Last year, Tepper delivered a 42 percent return—outpacing even the S&P's nearly 30 percent gain. He was also the highest paid hedge fund manager of 2013, earning $3.5 billion.
During a memorable appearance on "Squawk Box" in September 2010, he said the Federal Reserve's asset-purchase program virtually guaranteed strength in stocks. His comments sparked what became known as "The Tepper Rally." Since then, the S&P has gained nearly 84 percent. The index was up 12 percent for 2014 as of Monday's close.
In May 2013, Tepper told "Squawk Box" the Fed has to taper to keep the stock market advance on an even keel. The term "taper" become common parlance on Wall Street, and gave rise to the phrase "taper tantrum" when the markets reacted to subsequent developments.
A year later, this spring, Tepper was more cautious, when speaking at SkyBridge Capital's SALT 2014 conference in Las Vegas, saying "don't be too frickin' long right now."