Art is the worst performing collectible

The headlines of the past year would make you think that art prices are exploding. There was the $142 million Francis Bacon painting, the $58 million balloon dog and the $1 million Picasso cigar.

But those pieces represent a tiny slice at the top of the art market. When you look at values in the broader art market, the picture becomes a little less flattering. (See this piece by James Stewart in The New York Times for the best analysis.)

According to a new report from Knight Frank and WealthInsight, fine art was the worst performing collectible last year, with prices down 3 percent. The performance is based on an index from Art Market Research, which includes old masters, European 19th century, impressionists, modern and contemporary.

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The report said the overall art market is still down from its 2011 peak. Granted, over a 10-year period, art is still a good investment, according to the report, with a return of 193 percent.

And art is still popular with the wealthy, since many see it as more than a financial investment. The survey showed that among people worth $30 million, art is "growing in popularity" among 44 percent of them—making it the most popular class of collectibles.

Art was followed by wine and watches—suggesting that pleasure matters more than profits when it comes to collecting.

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So if art was the worst investment last year, what was the best?

Cars were the best performing collectible in 2013, up 28 percent. Cars are also the top performer over a 10-year period, up 456 percent.

(Read more: )

Here is the full list of collectibles and their returns from 2012-2013:

—By CNBC's Robert Frank. Follow him on Twitter @robtfrank.