SIOUX FALLS (AP) – A South Dakota broker has been sentenced to serve three years in prison and ordered to pay back more than $400,000 for trying to hide huge losses while managing foreign exchange currency.

Federal authorities say David Astin, 38, of Hermosa, told the investor he had consistently received returns of 8% per month in his own account and promised the victim gains of 1 to 3%. Instead, prosecutors say, he lost hundreds of thousands of dollars and tried to cover it up with fraudulent statements and spreadsheets.

Astin lost $433,877. of the investor’s money and was paid more than $75,000, according to investigators.

U.S. District Judge Jeffrey Viken ordered Astin to serve three years of supervised release when his prison term is completed.