Sioux Falls crypto investor Wiener indicted on 29 counts in alleged $20 million Ponzi scheme

A federal grand jury has indicted Sioux Falls, South Dakota, crypto investor Benjamin Paul Wiener, 43, on 29 counts of wire fraud, money laundering, bank fraud, and aggravated identity theft, accusing him of running a $20 million Ponzi-style scheme that defrauded dozens of investors across South Dakota and Minnesota.

Wiener appeared before U.S. Magistrate Judge Veronica L. Duffy on July 10 and pleaded not guilty. He was released on bond, and his trial is scheduled to begin September 15, 2026. U.S. Attorney Ron Parsons announced the indictment, which was returned by a federal grand jury last month.

How the alleged scheme worked

Prosecutors say Wiener made false statements to persuade victims to hand over cash and digital assets to a cluster of companies he controlled, known as the Benaiah entities, which he had operated since at least 2018.

The entities allegedly raised roughly $25.1 million from investors. About $12 million was eventually returned to them, while prosecutors allege Wiener funneled approximately $5.7 million toward personal expenses.

When investor funds ran low, or a client asked for their money back, Wiener allegedly solicited new investors and used their money to repay earlier ones, the classic mechanics of a Ponzi scheme. To conceal the source and ownership of the money, prosecutors allege he moved funds through banks and cryptocurrency exchanges.

A court-appointed receiver began investigating Wiener’s entities in August 2025 after investor complaints, and that inquiry fed into the federal case brought roughly ten months later.

A separate bank fraud charge

Prosecutors also allege Wiener obtained a $1 million line of credit from a Sioux Falls financial institution in April 2025 by submitting falsified documents and using another person’s identifying information without authorization, the basis for the aggravated identity theft count.

If convicted, Wiener faces up to 20 years in prison on each wire fraud and money laundering count, up to 30 years for bank fraud, and a mandatory consecutive two-year sentence for aggravated identity theft. Restitution to victims may also be ordered. The case is being investigated by the FBI and IRS Criminal Investigation.

Part of a costlier pattern

The case lands amid a sharp rise in crypto-related fraud nationally. The FBI’s Internet Crime Complaint Center reported more than $11.36 billion in cryptocurrency-related losses in 2025, up 22% from the prior year, out of roughly $20.9 billion in total internet crime losses.

Investment fraud was the single largest driver, accounting for about $7.2 billion of that total across more than 181,000 crypto-related complaints, with victims losing an average of over $62,000 each.

The FBI advises investors to independently verify companies, custody arrangements, and withdrawal policies before transferring funds, and to report suspected fraud to the Internet Crime Complaint Center as quickly as possible.