To Philip Horn, the Braemar Country Club was not just a golf course, it was an extension of his office. Most weeks, Mr. Horn, a financial adviser at Wells Fargo, chatted up potential clients between holes at the upscale club set against the backdrop of the Santa Monica Mountains.
"I always thought, 'This is a great guy and a straight shooter,' " said Barry Zelner, one of several country club members who invested with Mr. Horn.
Now, those same clients are wondering what went wrong.
After Wells Fargo alerted him to account discrepancies, Mr. Zelner, a corporate lawyer, said he stormed onto the club's rolling greens in April, accusing the broker of theft. "Tell them what you did, Phil," the lawyer bellowed among a crowd of members.
A few months later, Mr. Horn pleaded guilty to defrauding more than a dozen clients and Wells Fargo.
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While Mr. Horn is a relatively minor player in the pantheon of financial fraud, his actions highlight the persistent problems with policing the industry, even after the wave of rules enacted since the collapse of Bernard L. Madoff's giant Ponzi scheme in 2008.
And the challenge of oversight is not becoming any easier, with the ranks of financial advisers swelling. As new regulations crimp profits, big banks like Wells Fargo are ramping up their brokerage businesses in an effort to make up for lost revenue.
Amid the renewed focus, banks have spent millions of dollars to beef up their compliance systems and improve their oversight. Regulators, too, have bolstered their efforts, increasing enforcement and adopting new measures.
Every month, the Financial Industry Regulatory Authority, a Wall Street watchdog, penalizes more than 100 brokers for various actions, including unauthorized trading and fraudulent activities, as well as smaller violations.
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"Theft, Ponzi schemes and other financial scams continue to happen at an alarming rate," said Thomas Ajamie, a plaintiff's lawyer who represents two of Mr. Horn's clients.
For more than two years, Mr. Horn systematically executed and canceled trades in clients' portfolios, pocketing the profits. To avoid detection, he limited his paper trail and made it appear that the trades originated in his own account, according to court documents.
"It's simply unbelievable to me that this kind of fraud could happen for so long without Wells Fargo doing anything about it," Mr. Zelner said. After meeting Mr. Horn on the golf course, Derek Brown invested more than $10 million with him in 2006, assured by the Wells Fargo name on his business card. "This wasn't just Schlepper & Schlepper," Mr. Brown, a retired pharmaceutical executive, said.
A Wells Fargo spokeswoman, Raschelle Burton, said the bank discovered the problems with Mr. Horn in October 2011 and immediately alerted law enforcement agencies. Wells Fargo also fired Mr. Horn. Mr. Horn is set to be sentenced on Monday. Prosecutors have recommended an 18-month sentence. A lawyer for Mr. Horn declined to comment.
Some of Mr. Horn's clients are struggling to understand the extent of their losses. Mr. Brown and Mr. Zelner say that Wells Fargo has not let them review the trading records. Instead, they have had to rely on the bank's analysis. "The firm believes it has provided appropriate information," Ms. Burton said.
Prosecutors estimate the scheme's damages at $732,000. But there are indications the losses could be higher. Last year, Wells Fargo, without explanation, transferred roughly $500,000 to an account that Mr. Brown has at Merrill Lynch. Mr. Brown said he planned to file a lawsuit seeking additional compensation.
While some clients still have concerns, Wells Fargo said the matter had been resolved and declined to provide further details. "In cases where his actions harmed the clients, the firm has either credited those accounts or reached another resolution with those clients," Ms. Burton said.