Meet the Data-Obsessed Collector Tracking Whiskies Going for Millions on the Auction Block

There are three types of buyers for the world’s rarest Scotch whiskies: drinkers, collectors, and investors. Andy Simpson is all three.

“Today’s collectors provide liquid for tomorrow’s drinkers,” says Simpson. What he means by that is there’s a symbiotic relationship between the three: if people drank all the Scotch made in the past, there would be none to sell in the future.

Last year, U.K. auctions sold 107,890 bottles of Single Malt Scotch Whisky, more than triple the total in 2014. It turns out Simpson isn’t just a rare whisky collector, he’s also the data-obsessed co-founder of Rare Whisky 101, which tracks the value and volume of whiskies sold at U.K. auctions.

Even amid the stress-inducing Brexit, Scotch whiskies are toasting massive valuation gains. Rare Whisky 101’s Apex 1000—a dynamic index that measures the hammer price of the 1,000 best-performing Single Malt Scotch sold at auction—has increased in value by nearly 163% over the past four years, besting the Dow Jones Industrial Average, Brent crude, gold, and even the stock performance of Diageo, the world’s largest liquor company deo .

“Scotch has cachet,” says Simpson. But the boon is also due to the increasing popularity and proliferation of online auction sales, making it easier for collectors and investors outside the U.K. to buy into a craze that’s reminiscent of Dutch tulip mania.

In 2012, auctions sold just 14,150 bottles of rare Scotch at a total value of 2.9 million British pounds. By comparison, in March 2019, 13,347 bottles sold at 5.5 million pounds. Nearly all transactions occurred online.

Edrington dominates the Scotch auction market: the top two sellers by volume are the privately-held company’s The Macallan and Highland Park brands. LVMH’s Ardbeg lvmhf , Remy Cointreu’s Bruichladdich, and Beam Suntory’s Bowmore round out the top five.

“[Macallan] is the whisky that made me like Scotch—it has that universal, approachable flavor profile,” says Nicolas Villalon. He’s paid to say things like that these days, as he serves as The Macallan’s brand education and prestige, helping manage the brand’s rare whisky portfolio.

But to his credit, Villalon is right: Macallan makes delicious, well-regarded whiskies. “Macallan makes drinkers go nuts,” says Simpson. “They have a fantastic back catalogue. There’s always a new release, something from 30 years ago a collector doesn’t have that excites them.”