So I saw in the news  that in Japan, a broker who intended to sell 1 share of a new telecoms company J Com for 600,000 yen (approx. $4,976.49) but instead sold 600,000 shares at 1 yen (approx. $0.0082) a piece with the potential total damage to be around 60 billion yen (nearly $500M) for the brokerage firm, Mizuho Securities. Investors saw the order and realized a brokerage firm messed up and was going in the tank but since they didn’t know who put in the order, a massive selling of all brokerage firm stocks occurred and the Nikkei 225 fell 2%. Mizuho also cancelled its holiday party. (At the end of the article, there’s an interesting list of other similar type of screwups in the stock market)
I bet you never screwed up that bad. What was your worst work mistake?