E-fit images have been issued of three men being hunted after raiders held three people at gunpoint and ordered the transfer of Bitcoins.
Four men entered a house in Moulsford, Oxfordshire, on 22 January and threatened two men and a woman with what looked like a firearm.
They then demanded they transfer the crypto-currency Bitcoin into another account.
The transaction was not successful, Thames Valley Police said.
One victim, who was outside the home in Offlands Court at the time of the raid, shouted for help when the men entered at about 09:40 GMT but was pulled inside by the offenders.
An occupant was then struck on the head and needed treatment at the John Radcliffe Hospital in Oxford, although they were not seriously injured, the force said.
No arrests have been made and Det Sgt Alan McIllwain has appealed for anyone who saw anything suspicious, particularly after 10:00 GMT on 22 January, to contact police.