Federal Prosecutors Say This Sioux Falls Crypto Investor Ran a $20 Million Fraud

A federal grand jury indicted Sioux Falls crypto investor Benjamin Paul Wiener, 43, on 29 counts tied to an alleged fraud scheme that prosecutors estimate cost victims roughly $20 million.

The charges include wire fraud, money laundering, bank fraud, and aggravated identity theft. Wiener pleaded not guilty on July 10 and was released on bond ahead of a September trial.

This Crypto Investor Allegedly Turned Dozens Into Fraud Victims

According to the indictment, Wiener solicited both money and digital currency from investors through his companies. He allegedly made false statements and fraudulent representations.

Dozens of victims across South Dakota and Minnesota were affected, prosecutors said. After collecting funds, Wiener allegedly moved the money to hide its source and ownership.

Prosecutors describe a structure common to Ponzi cases. When funds ran low or an investor sought a refund, Wiener allegedly recruited new investors. He then used that fresh money to repay earlier backers and cover personal expenses.

The laundering allegedly ran through both banks and cryptocurrency exchanges. This mixed flow of fiat and crypto helped conceal the activity, according to the government.

“As a result of Wiener’s conduct, the government alleges the estimated total loss is approximately $20 million,” the press release reads.

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Entities and Bank Fraud

Wiener allegedly operated the scheme through eight entities. Most carried the “Benaiah” name, including Benaiah Capital LLC and Benaiah Digital LP. The list also included Aslan Management LLC and Runway Four10.

Separately, prosecutors allege Wiener defrauded a Sioux Falls bank. In April 2025, he secured a $1 million credit line by falsifying documents, according to the indictment. He allegedly used another person’s identifying information without permission to do so.

The charges remain accusations, and Wiener is presumed innocent unless proven guilty. His trial is set for September 15, 2026.

The case joins a growing list of federal prosecutions targeting operators who allegedly defrauded investors and used crypto to move the proceeds. The Justice Department charged 265 fraud defendants in 2025, with intended losses topping $16 billion.

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