China has launched a probe into leaks of its economic data, which is now running a close second to US economic data as the world’s biggest market mover, the Wall Street Journal reported. A secretary at the National Bureau of Statistics (NBS) is one of five officials under investigation for leaking data for personal gain, state media reported this week. The government has attempted in recent months to improve the security of the data. At a news conference in April, NBS spokesman Sheng Laiyun said the bureau is taking steps to reduce the number of officials with advance access to data and the time from collection to publication. Illegal leaks of indicators including industrial output, consumer prices and real-estate investment give insiders an advantage in anticipating market reactions and taking profitable trading positions. Historical data shows markets have had an uncanny ability to price in surprising economic data on China before it is released: In 2010, for example, the markets fell 3.1% on January 20, the day before the release of data showing a surprise uptick in inflation. On January 21, the day of the data release, the markets closed flat.