Trading in natural gas futures exploded Thursday just about seven seconds before the government was set to release its weekly market-moving natural gas storage report.
According to data provided to CNBC by Eric Hunsader of analysis firm Nanex, $17 million worth of futures contracts changed hands in the moments leading up to the report's release, sending prices higher.
The report, released every Thursday at 10:30 a.m. Eastern, details how much natural gas the government holds at that time. Markets typically react instantly to the information. This week, the report showed an increase of the commodity in storage, in line with expectations.
(Read More: Thomson Reuters Gives Elite Traders an Edge)
It's not clear what sparked the spike, but the price of July 2013 natural gas futures moved up sharply during the run-up to the scheduled news release.
Hunsader said he has seen markets move before the weekly government report more often in recent years.
"Crunching through our historic data, we found the first instance of high trading activity in the seconds before the EIA Nat Gas report was Jan. 7, 2010," Hunsader said. "Since that time, there have been at least 23 other days with similar activity."
A spokesman for the Department of Energy's Energy Information Administration, which puts out the data, did not return a call for comment.
—By CNBC's Eamon Javers. Follow him on Twitter: @eamonjavers