Investors who put their fortunes in the hands of arrested New York money manager Bernard Madoff are waiting to hear how much of their stake is left.

The roster of potential victims in what prosecutors said was a $50 billion Ponzi scheme has grown exponentially longer in the past few days.

Madoff, 70, said in regulatory filings that he only had around 25 clients, but it has become apparent that the list of people who lost money may number in the hundreds or even thousands.

Among those who have acknowledged potential losses so far: Former Philadelphia Eagles owner Norman Braman, New York Mets owner Fred Wilpon and J. Ezra Merkin, the chairman of GMAC Financial Services.

A charity in Massachusetts that supports Jewish programs, the Robert I. Lappin Charitable Foundation, said it had invested its entire $8 million endowment with Madoff. The organization's executive director said she doesn't expect it to survive.

Other institutions that believed they had lost millions included The North Shore-Long Island Jewish Health System and the Texas-based Julian J. Levitt Foundation.

Hedge funds and other investment groups looked like big losers too. The Fairfield Greenwich Group said it had some $7.5 billion in investments linked to Madoff. A private Swiss bank, Banque Benedict Hentsch Fairfield Partners SA, said it had $47.5 million worth of client assets at risk.

The losses may have extended far beyond the coffers of the wealthy and powerful.

The town of Fairfield, Conn., said it placed nearly 15 percent of its retiree pension fund with Madoff. Officials were scrambling to determine how much of the $42 million remained.

Harry Susman, an attorney in Houston, said he represents a group of clients who had unknowingly become entangled in the scandal by investing in a hedge fund managed by Merkin, which then put almost all of its $1.8 billion in capital in Madoff's hands.

"They had no idea they had exposure," Susman said. He said his clients were now dumbfounded as to how the fund came to invest all of its holdings with just one man, especially since concerns had been circulating for years about Madoff's operations.

For decades, Madoff had dual reputations among investors. Many wealthy New Yorkers and Floridians considered him a reliable investment whiz. Others, more skeptical, had questioned whether his returns were real, pointing to the firm's secrecy and lack of a big-name auditor.

But when he met privately with a family member at his firm earlier this month, something clearly was amiss.

First, federal authorities say the 70-year-old Madoff surprised the unidentified family member by saying he wanted to pass out hefty annual bonuses two months earlier than usual, court papers said. Then, when challenged on the idea, he said he "wasn't sure he would be able to hold it together" if they continued the discussion at the office, and invited him to his apartment.

It was the beginning of a stunning meltdown for the former Nasdaq stock market chairman.

Madoff himself described his investment business as an unsophisticated "Ponzi scheme," according to investigators who interviewed him.

Perhaps more startling than the loss was that it apparently caught regulators and investigators off guard, only coming to light last week when Madoff's own family turned him in.

The core of the scheme - taking investments from one client to pay returns to another - "has been around since the beginning of time," said Marc Powers, a former Securities and Exchange Commission enforcement chief and head of the securities practice at Baker Hostetler.

The firm somehow pulled off the fraud despite being subject to examination by the SEC, Powers added. "You wonder how these things escaped the normally careful review of these regulatory organizations."

The latest dose of bad news in the world of finance has left Madoff's clients "panicked," said Stephen A. Weiss, a lawyer for several dozen investors. "These people are sorrowful. These people are angry. And many are now destitute."

The wave of ill will - fuel for inevitable lawsuits - was aimed at a man who had cultivated an image as a straight-shooter with a personal touch.

The day after his arrest, his company's Web site still boasted that "in an era of faceless organizations ... Bernard L. Madoff Investment Securities LLC harks back to an earlier era in the financial world: The owner's name is on the door."

It went on to say "Bernard Madoff has a personal interest in maintaining the unblemished record of value, fair-dealing, and high ethical standards that has always been the firm's hallmark."

Madoff's resume was the stuff of Wall Street legend: He founded his company in 1960 with $5,000 he earned in part working as a lifeguard on Long Island beaches while putting himself through Hofstra University Law School. It eventually became one of five broker-dealers that spearheaded the formation of the Nasdaq Stock Market, where he served as a member of the board of governors in the 1980s and as chairman of the board of directors in the early '90s.

By 2001, Madoff's firm was one of the three top market makers in Nasdaq stocks and the third-largest firm matching buyers and sellers of securities on the New York Stock Exchange, according to Baron's.

Investigators say Madoff's crime originated in a separate and secretive investment-advising business.

Madoff apparently kept the loss a secret even from his two sons and other family members who work at the firm until he and two of them retreated to his apartment occupying the entire 12th floor of an Upper East Side building on Dec. 9, according the complaint drawn up by an arresting FBI agent.

"It's all just one big lie," he told his family. He confided he had blown the money in what was "basically, a giant Ponzi scheme," the complaint added.

Several attorneys representing investors, however, have questioned how he could have acted alone, given the size of the alleged fraud and vast holdings of his firm.

According to the court complaint, Madoff told his family he expected to end up behind bars, but wanted to execute his own version of a bailout package by doling out $200 to $300 million he had left to family, friends and employees. After the meeting, a lawyer for the family contacted regulators, who alerted the federal prosecutors and the FBI.