WASHINGTON/LONDON, United States, March 25, 2026 (BSS/AFP) - Thousands of oil contracts -- a far higher volume than normal -- were traded 15 minutes before US President Donald Trump pledged to halt strikes on Iranian energy infrastructure, sending prices tumbling, data showed on Tuesday. Between 1049 GMT and 1050 GMT, 734 oil contracts changed hands, and in the next minute that number surged to 2,168 -- 16 times higher than the average observed through the day up to that time. Bloomberg estimated the value of oil contracts that changed hands between 1049 and 1050 GMT was $650 million. At 1105 GMT, Trump stepped back from a threat to attack Iranian energy sites, citing "very good" talks to end the war in a social media post. The statement sent crude prices plunging more than 14 percent in a fresh burst of trading activity. Traders who bet on prices dropping ahead of the announcement would likely have profited from Trump's sudden reversal, prompting analysts to question whether some market participants had acted on prior information. "What stands out here isn't just the size of the trades, but the timing," Stephen Innes, an analyst at SPI Asset Management, told AFP. "Traders are not clairvoyant. When positioning shifts minutes ahead of a market-moving headline, it usually means someone is acting on... intel before the story broke," he added. No evidence of insider trading had been established as of Tuesday. The Chicago Mercantile Exchange (CME) and the Commodity Futures Trading Commission (CFTC), the US regulator of financial derivatives, did not immediately respond to an AFP request for comment. The White House also did not respond to an AFP request for comment on the issue. - 'Mind-blowing corruption' - Similarly, S&P 500 stock index futures showed an unusual burst of trading activity early Monday, about 15 minutes before Trump's social media post, CNBC reported. US Senator Chris Murphy, responding to a social media post that alleged a single $1.5 billion purchase of S&P 500 futures just before Trump's announcement, called it an example of "mind blowing corruption." "A $1.5 BILLION BET... 5 minutes before Trump's post. Who was it? Trump? A family member? A White House staffer? This is corruption. Mind blowing corruption," the Democratic lawmaker said on X. The speculation about insider trading has also spread to prediction markets, which allow people to bet on the likelihood of thousands of global events. CNN reported that one trader made $1 million from dozens of well-timed bets on Polymarket that correctly predicted US and Israeli military actions against Iran. Based on findings from Bubblemaps, an analytics company that tracks blockchain transactions, this particular bettor has had a pattern of prescient bets, including hours before Israeli's October 2024 strikes on Iran, CNN reported. Innes noted that the oil market is "not just traders speculating on price; it's a tightly connected ecosystem of physical players, refiners, shippers and governments, all operating within overlapping information channels." He added that the activity could have been driven by a large producer hedging against a potential price drop, given that oil futures had surged 40 percent since the start of the war. A few hours after Trump's announcement, Tehran's parliamentary speaker, Mohammad Bagher Ghalibaf, reportedly involved in talks, said "no negotiations" were under way, insisting Trump was seeking "to manipulate the financial and oil markets."