"In short: US Democrats have called for an investigation into whether anyone in Donald Trump's circle engaged in market manipulation.
"The president told followers on social media it was a great time to buy stocks, hours before his tariff decision on Wednesday.
"Within minutes of Mr Trump's social media post, the S&P 500 shot up more than 7 per cent.
"Democratic senators are calling for an urgent investigation into US President Donald Trump and his inner circle — including senior adviser Elon Musk, intending to find out if any market manipulation took place following his policy shift on 'Liberation Day' tariffs.
"Global markets plummeted in the days after President Trump announced select trading partners would be charged tariffs of up to 49 per cent on April 2. The S&P 500 shed $5.83 trillion in four days, representing its steepest losses since the index was created almost 70 years ago.
"But on the morning of April 9, Mr Trump began offering his followers reassurance in posts to Truth Social: 'BE COOL! Everything is going to work out well. The USA will be bigger and better than ever before!'
"Minutes later, he elaborated: 'THIS IS A GREAT TIME TO BUY!!! DJT'
"It is not common for the US president to sign off with his initials. DJT is also the NASDAQ ticker for Trump Media and Technology Group, the operator of the social media platform Truth Social.
"About four hours later, Mr Trump announced a delay of 90 days on the tariffs in another social media post, choosing instead to impose a 10 per cent tariff in the interim.
"Within minutes of Mr Trump's social media post, the S&P 500 shot up more than 7 per cent. It finished the day up 9.5 per cent — its biggest one-day gain since 2008. The Nasdaq composite saw its second-largest session surge on record to finish 12.2 per cent higher.
"Democratic senators are now calling for an 'urgent inquiry', claiming the US president created circumstances where market manipulation could've taken place.
"'This sequence of events raises grave legal and ethics concerns,' Senator Adam Schiff said in a letter to the US Office of Government Ethics.
"'The president, his family and his advisers are uniquely positioned to be privy to and take advantage of non-publication information to inform their investment decisions.'
"Mr Schiff then cited Elon Musk as an example, claiming his position as a senior government adviser grants him access to information not available to the public that could affect his vast business interests.
"'Stock in Elon Musk's company, Tesla, increased 18 per cent immediately following the president's announcement to pause most tariffs,' Mr Schiff said.
"'The apparent conflict of interest issues President Trump's announcement presents regarding Mr Musk apply to all White House and executive branch employees — including special government employees — who may have access to non-public information regarding the deliberations and ultimate changes in tariff policy.'
"Democratic senator Chris Murphy said the US president telegraphed to his social media followers that they should buy stocks, alleging 'this could be an enormous scam'.
"'Trump's position changing every single hour gives ample opportunity for any individual who has early access to information … to make boatloads of money, either by investing at the right time or pulling their money out of the market at the right time,' he said in a video posted to social media.
"The Democratic senators allege Mr Trump's conduct presented opportunities where the market could've been manipulated.
"Market manipulation occurs when someone artificially affects the supply or demand for a security, such as causing stock prices to rise or fall dramatically.
"According to the United States Security and Investment Commission, it involves techniques that spread false or misleading information about a company, and by making a security appear either more actively traded or in less demand."