The FBI has joined an investigation into the suspicious disappearance of a Southern California grandfather, which his family believes could be tied to their success in the cryptocurrency business.

Federal authorities recently became involved in the probe for missing Rancho Cucamonga resident Naiping Hou, 74, who is the father of noted hedge fund and cryptocurrency investor Wen Hou. The son serves as the chief investment officer at Coincident Capital. In 2022, Wen Hou and his wife, who live in Las Vegas, contributed $1.1 million in cryptocurrency to the USC Keck School of Medicine to help fund research on heart disease.

Naiping Hou was last seen in his hometown on March 18, 2025. He was officially reported missing on May 4, 2025, after…