Sarao canceled 99 pct of orders-CFTC civil complaint

April 23 (Reuters) - Navinder Singh Sarao, the futures trader charged with market manipulation that contributed to the May 2010 Wall Street "flash crash," was canceling more than 99 percent of his orders on days examined by the U.S. Commodity Futures Trading Commission, according to civil-case documents filed with the U.S. District Court of Northern District of Illinois.

The CFTC asked Terrence Hendershott, a professor at University of California-Berkeley, to examine Sarao's activities to determine whether they had a legitimate business purpose.

The days he examined showed that Sarao canceled more than 99 percent of the orders that he submitted through his algorithm, whereas other traders with orders larger than 200 lots canceled only 48 percent of the time.

They also found that Sarao modified his orders, on average, 161 times, compared with an average 0.1 modification for other traders' orders.

Hendershott declined comment when reached by Reuters. Sarao, 36, is accused by U.S. authorities of using an automated program to "spoof" markets by generating large sell orders that pushed down prices. (Reporting by David Gaffen)