Family offices use encrypted chats to share deal flow, with WhatsApp increasingly serving as a one-stop network to vet opportunities, find advisers and flag potential scams, even as cyber-security specialists warn that consumer-grade controls can create risks. Sam Nallen Copley, a London-based adviser, runs a 970-member group for single-family offices and said the chat can quickly “sense check” unknown counterparties and weed out fakes. Professionals said WhatsApp often beats