OneCoin, founded by Ruja Ignatova in 2014, became infamous as one of the largest cryptocurrency Ponzi schemes in history.

Promoted as a revolutionary cryptocurrency, OneCoin lured in millions of investors from around the globe, claiming to have a legitimate blockchain.

However, it turned out that the "blockchain" was merely a database on an SQL server, and no actual cryptocurrency was ever created.

Ruja Ignatova, known as the "Cryptoqueen," disappeared in 2017, shortly after law enforcement started closing in.

Since then, her brother Konstantin Ignatov took over but was arrested in 2019.

The scheme defrauded investors of an estimated $4 billion, although some reports suggest the total losses could be as high as $19 billion.

Ignatova remains on the FBI’s Ten Most Wanted list, with a reward of $100,000 for information leading to her arrest.

Meanwhile, key figures like Karl Sebastian Greenwood were sentenced to prison for their involvement