In 2022, Shan Hanes, the chief executive of the Heartland Tri-State Bank in Kansas, met a friendly investment adviser from Australia on WhatsApp. The adviser persuaded Hanes to invest a few thousand dollars in an online cryptocurrency-trading platform, which generated impressive returns. Hanes ended up investing all his own money, $60,000 from his daughter's college fund, $40,000 from his local church and $47 million from the bank he ran. The “a…