When a pack of wine collectors arrived in the private second floor of Manhattan's Bowery Hotel last Thursday for an auction held by Acker Merrall & Condit, they weren't there to hold back. Before guests started waving white paddles to bid on 730 lots of wine—several of which went for tens of thousands of dollars and set world records—fellow collectors chatted over a tasting table.

It was an enthusiast's dream. The spread included a slew of wines from every major region: Among them, a 1937 red Burgundy and an ice bucket loaded with three magnums (1.5 liters each) of Krug champagne. To a casual observer, the scene shouted "bull market."