In a striking pre-market move, trading volumes for S&P 500 and WTI oil futures spiked sharply minutes before President Donald Trump's social media post about U.S.-Iran negotiations, which subsequently triggered significant market movements.
Unusual Volume Spike in Early Trading
- At approximately 6:50 a.m. ET on March 18, 2026, S&P 500 e-Mini futures on the CME experienced a sudden and isolated jump in volume during otherwise subdued premarket conditions.
- This occurred amid typically low liquidity in early trading hours, making the spike one of the largest volume moments of the session up to that point.
- Simultaneously, West Texas Intermediate (WTI) May crude oil futures saw a distinct pickup in trading activity around the same time, interrupting quiet market conditions.
Trump's Announcement and Immediate Market Reaction
- Roughly 15 minutes later, at 7:05 a.m., President Trump posted on Truth Social that the U.S. and Iran had held talks and he was halting planned strikes on Iranian energy infrastructure.
- Following the announcement:
- S&P 500 futures soared more than 2.5% before the stock market opening.
- WTI crude futures dropped nearly 6%.
Scrutiny Over Timing and Potential Explanations
- The coincidence of the volume spikes preceding the market-moving news has drawn attention from traders, given the absence of an obvious catalyst at the time.
- In low-liquidity pre-market sessions, large trades can be more noticeable and potentially profitable, as those who bought stock futures and sold or shorted oil futures just before the post gained significantly.
- Experts note that algorithmic and macro-driven strategies can generate rapid cross-asset flows without a single identifiable trigger, especially in early trading.
- The U.S. Securities and Exchange Commission and CME Group did not immediately respond to requests for comment on the unusual activity.