Mumbai: He was supposed to sell one share for 610,000 yen ($5,065 or Rs2.30 lakh). Instead, 610,000 shares — valued at $3.1 billion — were offered for just 1 yen (1.2 cents or Rs5.52) each! Apparently, somebody made a very costly typing mistake at the brokerage unit of Mizuho Financial Group, Japan's second-largest bank.

The error ultimately cost the brokerage house around 27 billion yen ($224 million or Rs1,030 crore), as it tried to buy back the shares after a whirlwind of trades. Makoto Fukuda, Mizuho Securities' president, was deeply apologetic as he addressed a press conference in Tokyo after the fiasco. "It should never have happened, but someone unintentionally ignored the alerts," he said.

Market watchers around the world have expressed concern about what seems to be grossly inadequate control functioning of the stock order system. The outrageous sell orders in J-Com stock made it the most actively traded stock on Thursday. The Osaka-based staffing company had sold just 2,800 shares in its initial public offering (IPO) earlier this month.

Though the brokerage house realised its mistake within three minutes, four attempts to cancel the order failed. Even the bank's central office couldn't stop it. Finally, Mizuho decided to buy back most of the shares.

Within those three vital minutes, J-Com shares fell by the maximum 15 per cent limit, from its issue price of ¥610,000 to ¥572,000. Over the next eight minutes, close to 700,000 shares were traded, including one order for about 467,000 shares, valued at $2.2 billion (Rs10,120 crore). J-Com stock finally closed at ¥772,000 yen, up by the maximum permitted 15 per cent. The shares were suspended from trading on Friday.

Because of market rules limiting price fluctuations, the shares could not be bought for 1 yen but may have been sold as cheaply as ¥572,000 yen each. But who gained? Market gossip points the finger at day traders, who could have made a killing selling the shares to institutional investors.

The losses at Mizuho could well result in sackings, reduced salaries and maybe even a government inquiry. Mizuho shares fell by around 1.4 per cent, immediately following the incident.

This is by no means the first error on the Tokyo Stock Exchange (TSE). On November 30, 2001, UBS AG sold over 600,000 shares in advertising firm Dentsu Inc for 16 yen apiece, instead of the IPO price of ¥420,000 yen. Observers feel the problem is unique to Tokyo's stock exchange.