Stanislaus County accountant pleads guilty in $7 million Ponzi scheme

A Stanislaus County tax preparer and accountant is facing multiple years in prison after pleading guilty to a long-running Ponzi scheme that duped dozens of investors out of more than $7 million dollars, federal authorities said.

Turlock resident Antonio Honorato Silveira, 50, pleaded guilty on Monday to wire fraud in a scheme that began in 2011, U.S. Attorney for the Eastern District of California Eric Grant announced in a press release.

According to court documents, Silveira would invest money on his clients' behalf, promising annual returns of between 13% and 17% and memorializing the promises in signed promissory notes and guarantees. The clients gave Silveira discretion to invest their money in the stock market as he saw fit, prosecutors said.

However, Silveira was unsuccessful at trading stocks and consistently lost money, the U.S. Attorney's Office said, and he also diverted investor funds to pay his own expenses. By 2017, he wrote to three investors stating, "I no longer have any money, it was all lost. Doesn't appear to be any new investors in sight either ... This whole experience has been terrible and I apologize." 

Despite the acknowledgment and apology, prosecutors said Silveira continued to solicit new investors. Between 2019 and 2025, nearly 90 investors gave Silveira about $11.03 million, he knew he could not pay the returns he promised, according to the office. During that period, Silveira only had two profitable years and five in which he lost money, with the losses in each down year exceeding the gains of any single profitable year, prosecutors said.

During those loss years, Silveira used approximately $3.84 million of investor funds as payments to investors falsely portrayed as investment returns, prosecutors said. 

When the scheme collapsed in 2025, Silviera owed investors approximately $7.19 million. More than 25 investors suffered losses that included their retirement savings or college funds, delayed retirements, and the sale of a home, according to prosecutors. 

Silveira was scheduled to be sentenced in February 2027 and faces a maximum of 20 years in prison. His actual sentence will take into account federal guidelines and other variables.