Citadel Securities Fined 11.88 Bn Won over Stock Algorithm Trading Breaches by South Korea

South Korea's financial regulator has imposed a fine of 11.88 billion won ($9.66 million) on U.S.-based Citadel Securities, saying it disturbed the local stock market with high-frequency algorithm trading.

The Financial Services Commission (FSC) said in a statement released on Thursday the firm had distorted stock prices with artificial factors, such as orders on the condition of "immediate or cancel" and by filling gaps in bid prices.

The firm carried out such trading on an average of 1,422 stocks per day from Oct. 2017 to May 2018, totalling more than 500 billion won worth of trades, according to the statement.

The Commission said it was the first time it had imposed fines on such high-frequency trading on the South Korean stock market, which has a high proportion of retail investors and little competition among algorithmic traders.

It added the firm did not provide algorithm source codes in the consultation process.

(Source: Reuters)