Hackers Manipulate Markets in $700 Million Illicit Trading Spree

Criminals are hijacking online brokerage accounts in Japan and using them to drive up penny stocks around the world. The wave of fraudulent tradinghas reached ¥100 billion ($710 million) since it started in February and shows no signs of cresting.

The scams typically use the hacked accounts to buy thinly traded stocks both domestically and overseas, allowing anyone who has built up a position earlier to cash out at inflated values. In response, some Japanese securities firms have stopped processing buy orders for certain Chinese, US and Japanese stocks.

Eight of the country’s biggest brokers including Rakuten Securities Inc. and SBI Securities ...