April 9 (Reuters) – The White House warned staff against improperly leveraging their positions to place bets in futures markets in an email on March 24, a day after President Donald Trump ordered a brief pause in some Iran strikes, a White House official said on Thursday.

Some of Trump’s major policy decisions have been preceded by well-timed bets, leading some experts to question whether information had somehow leaked ahead of time. In the latest example, investors placed an approximately $950 million bet on oil prices just hours before the U.S. and Iran announced a ceasefire on Tuesday.

Exchange data showed similarly well-timed bets on oil futures in March shortly before Trump called a delay in attacks on Iran’s energy infrastructure. Lucrative bets in prediction markets, which allow traders to bet on “yes” or “no” outcomes on specific events, have also drawn scrutiny.

The well-timed trades have led legal experts and lawmakers to call for scrutiny as to whether they are based on inside information or leaks.

The Wall Street Journal, which was first to report the White House’s warning, said the announcement was made in a staff-wide email from the White House management office.

“While he (Trump) seeks a strong and profitable stock market for everyone, members of Congress and other government officials should be prohibited from using nonpublic information for financial benefit,” White House spokesman Davis Ingle told Reuters in a statement.

(Reporting by Mrinmay Dey in Mexico City and Angela Christy in BengaluruAdditional reporting and writing by Chris Prentice in New York; Editing by Chris Reese and Philippa Fletcher)