Crypto Traders Seek Out Extra Security as Kidnappings Rise

To maintain an edge in the volatile, non-stop world of cryptocurrency trading, it helps to be chronically online. Telegram, Discord and Reddit forums are full of investors swapping tips, memes and — when they get lucky — posting screenshots of gains. Flexing big-ticket purchases like sports cars and designer watches is an easy way to signal credibility and clout.

Such flashy displays, however, aren’t only attracting attention from envious onlookers, but also criminals on the lookout for clues that could help them put a real name or address to a pseudonymous trader.

As the price of Bitcoin and other ...