Rep. Ritchie Torres, D-N.Y., on Wednesday called for a federal probe into suspicious trading activity in oil and equity futures markets just before President Donald Trump’s announcement of a five-day delay in attacks on Iran’s energy infrastructure in March.

In a letter to Securities and Exchange Commission Chair Paul Atkins and Commodity Futures Trading Commission Chair Michael Selig, first reported by CNBC, Torres cites reports on a series of irregular and well-timed trades in the minutes ahead of Trump calling a pause on hostilities.

“What kind of trader would make a massive trade at 6:49 a.m., 15 minutes before a market-moving presidential announcement with billions of dollars at stake and without a hedge?” Torres said in an interview on Wednesday. “The only plausible answer to that question is an insider trader. Any other alternative is a statistical impossibility.”

More than $500 million in crude oil futures trades were made in the roughly 15 minutes before Trump announced the halt in strikes via Truth Social, Reuters reported last month. The New Yorker reported that in the immediate lead-up to Trump’s announcement, there was an abnormal surge in futures trading volume predicting a decline in oil prices and a rebound in equity markets.