Of course, few will have sympathy for wealthy oenophiles crying over their spilled Margaux. Yet the victims also include teachers, doctors, accountants and wine store workers who used their savings to buy special-occasion wines with Premier Cru.

“Sure it hurts,” said Ned Valois, a retired Florida policeman who may have lost $800 to Premier Cru. “I got suckered into it by the prices. They seemed too good to be true, and they were.”

Premier Cru’s collapse has sent a chill through the broader wine and collectibles market. As wine, art, classic cars and other collectibles have soared in value and transformed from status trophies into financial investments, they have also become more prone to fraud. Although fake vintage wine has dogged the industry for years, there are signs that wine fraud has reached a new “financialized” stage, where millions of dollars are lost without a single bottle changing hands.

Premier Cru started out as a low-price wine shop for high-income collectors. Founded in 1980 by Mr. Fox and other partners, it outgrew its store in Emeryville, Calif., and in 2011 opened its gigantic emporium on University Avenue in Berkeley.

Clients said Mr. Fox was the driving force behind Premier Cru. Tall, businesslike and better known for his taste in fast cars than fine wine, Mr. Fox often dealt with Premier Cru’s biggest clients and orders. Much of Premier Cru’s business came online. Clients say wine buyers often search the Internet for the best prices for top wines, and Premier Cru often undercut its competitors by 15 to 20 percent — significant savings for wines that may sell for more than $1,000 a bottle.

In the 2000s, Premier Cru started expanding its business of selling wine futures, according to clients. Futures allow customers to pay for wine (usually Bordeaux or Burgundy) while it is still in the barrel but is not yet bottled or sold in retail outlets. The wine is delivered more than a year later. If a wine increases in value while it’s aging, the buyer gets the wine at a discount. Some buyers can also use futures to buy wine they can later flip for a profit, making futures more like a financial investment.

Thomas Boothe, a lawyer in Portland, Ore., started buying wine and futures from Premier Cru in the late 1980s, he said. He talked with Mr. Fox several times over the years.