If you think stocks are rising faster than expected, consider prices for collectible Ferraris.
Since 2010, the average price of collectible Ferraris is up more than 70 percent, according to Hagerty, the collectible-car insurer and valuation firm. Hagerty's Ferrari Index – composed of values for 13 of the most in-demand Ferrari models of the 1950s to the 1970s - has far outperformed the 43 percent growth in Hagerty's "Blue Chip" Index. The Blue Chip is a broader index of 25 of the most sought after collectible cars in the post-war era.
The average price of the Ferraris in the index has now topped $2.6 million.
So do Ferrari prices still have room to run, or is it a bubble? We'll get some hints this weekend at the Amelia Island Concours d'Elegance in Florida – one of the top car-collector events of the year. Among the top Ferrari lots is a 1952 Sport Berlinetta being sold by RM Auctions that could fetch up to $1.4 million. RM Auctions, the main auctioneer at Amelia, is also selling a 1965 GTB that could sell for $1.3 million.
The top Ferrari price of the weekend could go to a bright yellow 1966 Ferrari 275 GTB long-nose that could top $2 million. It's being sold by Gooding & Co.
(Read more: World's Largest Trove of Tiny Cars Goes to Auction)
The big price increases are on the '50s-'60s era GTs and GTOs, which are considered the heart and soul of Ferrari's racing tradition and craftsmanship. The highest price ever paid for a vintage Ferrari is the $35 million paid for a 1962 Ferrari GTO last June.
Marcel Massini, founder of Massini AG and one of the world's top experts and historians on collectible Ferraris, said that in December and January alone, seven Ferrari 250 GT SWB Berlinetta's sold in private deals, or outside of auctions, for a total of more than $50 million.
That's more than two or three times the typical number sold, he said. "I've never seen this level of activity in this market, ever," he said.
Massini said that one Ferrari collector in the United States was offered $50 million for his GTO in recent weeks, but he turned it down.
"He doesn't need the money and he loves the car," Massini said.
In other words, the price was too low. But Massini said that it's likely that a GTO will sell for $50 million or more in the coming years. With rising wealth around the world from stock markets and prices rising for all manner of hard assets – from real-estate to art and cars – Ferrari prices still have room to run.
And they're not making any more vintage Ferraris. Ferrari only made around 165 of the 250's between 1953 and 1964. They made only 36 GTO's – considered the most sought-after Ferrari for its success on the racetrack – between 1962 and 1964.
"You're buying a legend with the 250," Massini said. "You have all this money out there, new money, and this new generation of buyers can buy whatever they want. If they can buy a legend, they will."
Massini said that the buyers of the GT's are not speculators or "flippers" and almost all of them plan to hold on to the cars and even drive them for years. That's another sign, he said, that prices at the very top of the Ferrari market will hold up.
Where prices may soften in the future, he said, are for the Ferrari Dinos and Daytonas, which don't have the same legacy as the GTs but have also seen a surge in price.
"Some people have said there might be a little bit of a bubble forming with those cars," he said. "But not the GTs and GTOs."