President Donald Trump has sparked yet another massive reversal in global markets. Trump on Monday posted on Truth Social that the U.S. and Iran held “productive” talks over the weekend. This came after Trump gave Tehran an ultimatum: Open the Strait of Hormuz, or the U.S. will attack key energy infrastructure in Iran. The post sent stock futures — which were sharply lower entering the day — soaring. Contracts tied to the Dow Jones Industrial Average were up around 1,000 points. S & P 500 and Nasdaq-100 futures popped 2% each. Crude futures tumbled , and gold prices cut losses. It was a shockingly rapid reversal. “Depending on what time you got on the elevator to your office meant more than 100 bps in futures,” said Deutsche Bank’s trading desk in an email. @SP.1 5D mountain S & P 500 futures 5-day chart Monday’s early trading action gives “TACO” trade vibes on Wall Street. TACO is an acronym for “Trump Always Chickens Out”, which was popularized in 2025 as the president would seemingly issue sky-high tariffs on countries only to settle on a much lower levy, hence the “chickens out” part of the abbreviation. “Like we learned during the Tariff escalation, it is typical with Trump that he’ll feed positive news prior to moments of finality and in this case, he is desperately looking to get the Strait of Hormuz open as it’s inflicting pain across markets, so we can start seeing the same playbook,” Citi’s trading desk wrote in a note. Stocks that have struggled since the war began got a boost. JPMorgan Chase and Goldman Sachs — down 4.6% and 5.4%, respectively this month — gained more than 2% each. Travel names such as Delta Air Lines and Carnival both popped more than 6%. There’s just one problem: Iran contradicted Trump’s post, with state media denying the discussions over the weekend even took place , meaning Monday’s early surge could be short lived. “Head on a swivel as the tweet heard round the world is rattling markets this morning after a tumultuous weekend of headlines and a dicey Monday open,” said Wells Fargo’s trading desk. “It’s still early, but my sense is that investors remain skeptical. The market continues to be un-tradable and un-investable.” One level investors should watch is the 200-day moving average on the S & P 500, according to Jay Woods of Freedom Capital Markets. The S & P 500 closed below that mark last week for the first time since May. However, Monday’s futures surge points to the benchmark trying trade back above it. “Can the S & P rally to its 200-day moving average at 6621 and then recapture it? Look for relief rallies in beaten down sectors like technology and discretionary to start the week, but rhetoric given only a 5 day reprieve may prevent a stronger and more lasting rally. The trade for now is to fade until we get more news out of Washington,” Woods told CNBC.