If you look at the stock market over the last 10 years, it's plain to see that even bellwether stocks have been very volatile, to say the least. In the late '90s, everyone wanted to be in the markets and that was bad for the big-ticket auction houses, even as the bubble produced many new millionaires and billionaires.

Then came the recession and that was also bad for the auction companies, as people simply did nothing for several years. Now, as the economy picks back up, investors are active once again, but they clearly want to be more diversified. Money has poured into exchange-traded funds, international equities, and commodities.

Now investors appear to be looking harder at collectibles, too. Sotheby's Holdings (NYSE:BID) took in $59.1 million in auction-related revenue during the first quarter compared to $38.1 million a year earlier. Its earnings were convoluted due to taking in an additional $45 million in revenue related to a onetime license fee it received from Cendant (NYSE:CD) in conjunction with the sale of its real estate brokerage business. The company reported net income of $13.5 million, ($0.22 a share), but not counting the onetime licensing fee it lost $14.8 million, ($0.24 a share), compared to a loss of $27.6 million, ($0.45), a year earlier.

The revenues are there if the company can figure out how to turn them into profits. What might help would be if the sale of Picasso's "Boy With A Pipe" for a record $104.2 million prompts art collectors to put other high-dollar pieces on the market. It could also spark an even greater investment interest in a wide range of collectibles. That could also help Greg Manning (NASDAQ:GMAI), and even online auctioneereBay (NASDAQ:EBAY), if the contagion catches on with the not so high-dollar collectors as well.

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Fool contributor Mark Mahorney doesn't own shares of any companies mentioned.