Trading blunders: This month, the Tokyo Stock Exchange

It seems trading errors on the Tokyo Stock Exchange are contagious. After local trader Mizuho Securities triggered a panic sell-off in a local recruitment company in December by incorrectly inputting order instructions, another large Tokyo trading firm, Nikko Citigroup, mistakenly purchased one thousand times more shares in a company than it intended in January.

First prize for trading error of the month, however, goes to Daiwa Securities SMBC. The firm placed a sell order for the wrong company entirely, triggering a sharp fall in the share price before realizing its error and buying back the shares already sold.