On Thursday 8th of December 2005 was a red letter day for the Tokyo Stock Exchange and Mizuho Securities. This happened when a trader at Mizuho Securities tried to sell 610,000 shares at 1 yen (less than a penny, actually about 0.8 cents) apiece of a job recruiting firm called J-Com Co. , which was having its public debut on the exchange. This concluded the single most expensive mistake in the stock exchange history, not just in Tokyo alone.

It had actually intended to sell 1 share at 610,000 yen (as at 2005, $5,041).

Read More here: http://factwide.com/2015/12/expensive-mistake-stock-exchange-history/

My question is, if it was you that was the stock broker or company owner, what would you have done?