An iconic drip painting by Jackson Pollock from the collection of S.I. Newhouse fetched $181 million at Christie’s last week . The price for Number 7A (1948) was heralded around the world as exceptional. But was it an exceptional investment? Newhouse bought Number 7A for $32 million in a private transaction in 2000, according to Alex Rotter , Christie’s global president. Over 26 years, the annualized return for the Pollock comes to about 6.6 percent, not including carrying costs like insurance. Over the same period, a passive investment in the S&P 500, with dividends reinvested, would have grown to about $240 million—outperforming the Pollock while offering greater liquidity and lower costs. Auctioneer Adrien Meyer sells Jackson Pollock’s Number 7A (1948), the top lot of the S.I. Newhouse sale, for $181.2 million. Courtesy of Christie’s. And Number 7A —the top lot of the $2.5 billion May auction season in New York—was the best of the best.…