Global markets swing on US–Iran war headlines as risk-on rally falters – a cross analysis on S&P 500, US Dollar Index, AUD/USD, and WTI crude

• Volatility driven by conflicting war narratives: The S&P 500 and Nasdaq 100 swung between risk-on and risk-off as mixed signals on US–Iran negotiations triggered sharp reversals, while prediction markets still show low near-term ceasefire odds.
• Cross-asset signals point to fragile sentiment: The US Dollar Index remains supported, AUD/USD failed at resistance, and WTI crude oil holds key support—indicating no clear shift to sustained risk-on positioning.
• Technical resistance caps upside, downside risks persist: Equities are struggling at key moving averages (e.g., S&P 500 at 200-day MA), with downside triggers still in play—suggesting markets remain vulnerable to further declines despite intermittent rebounds.

The global markets have once again seen a “wild swing of the pendulum” in the past eight hours, driven by conflicting news narratives related to the ongoing US-Iran war, which has lasted 25 days as of Tuesday, March 24, 2026.

Tuesday’s session marked a mild reversal from Monday’s sudden burst of risk-on behaviour triggered by US President Trump’s claim that the US and Iran are back on the negotiation table, and a deal is imminent to end the conflict. Iranian officials refuted such claims, which led to a sell-off in global equities, a rebound in the US dollar, and a decline in benchmark oil prices, accompanied by an intraday softening of gold and silver.

By the end of Tuesday’s US session, three major benchmark US stock indices ended with losses; S&P 500 (-0.37%), Nasdaq 100 (-0.77%), and Dow Jones Industrial Average (-0.18%), with a slight risk-off backdrop backed by an increased odds that the US White House is sending military ground forces to Iran to odd US-Israel joint offensive as media reports stated that US administration has ordered the 82nd Airborne Division to deploy around 2,000 soldiers to the Middle East.

At around 4.15 am Singapore time, Wednesday, 25 March (right after the close of Tuesday’s US session), US President Trump gave a press conference that signalled that Iran had offered a “present” as a show of good faith in negotiations he has claimed are ongoing, hinting at a possible ceasefire to happen “very soon”.

The S&P 500 and Nasdaq 100 e-min futures rose sharply at the start of Wednesday, 25 March Asian session, with an intraday gain of 1% before it dwindled to 0.7% at this time of writing.

However, Polymarket’s prediction market platform is not reflecting an imminent US-Iran ceasefire, and several key cross assets’ price action behaviour is not displaying clear signals of an all-out risk-on herd sentiment at this juncture.

Unfolding them as follows…

Data sourced from Polymarket compiled by fundamental data provider, MacroMicro, has indicated that the prediction market-implied probability for a US-Iran ceasefire by 31 March 2026 has only increased slightly to 17.5% on Wednesday, 25 March at this time of writing from its prior day of 12.5% (see Fig. 1).

A higher probability of a ceasefire at 62.5% is being priced in at a longer period, by 31 May 2026 (a jump from 56.5% printed on Tuesday, 24 March).

The current price actions of the US SPX 500 CFD index (a proxy of the S&P 500 E-mini futures) have its intraday rally cut short again at its 200-day moving average, now coinciding with the 6,648 key short-term pivotal resistance (see Fig. 2).

A breakdown with an hourly close below 6,540 near-term support (downside trigger) may open up scope for the bears to retest Monday’s 23 March 2026 swing low area at 6,470/442 in the first step.

The recent 1.6% decline seen in the US Dollar Index from its 100.10/100.54 medium-term range support has managed and continued to find support at the 99.00 level, which confluences with the 20-day moving average and the ascending trendline in place since the 27 January 2026 low of 95.55 (see Fig. 3).

The Australian dollar is considered a proxy of risk appetite, where a rally in the AUD/USD represents a risk-on behaviour.

On Wednesday, 25 March, the Asian opening session intraday rally seen in the AUD/USD has been wiped out after a bearish reaction right at the 50-day moving average, with an intraday loss of 0.4% at this time of writing.

Watch the 0.7027 key short-term pivotal resistance on the AUD/USD, and it has staged a bearish breakdown from a minor “Head & Shoulders” bearish reversal configuration on Monday, 23 March 2026 (see Fig. 4).

A break below 0.6910 key medium-term pivotal support exposes further potential weakness towards the next intermediate support at 0.6838 in the first step.

Wednesday’s Asian opening session sell-off seen in the West Texas Oil CFD index (a proxy of the WTI crude oil futures) has managed to find support once again at the 20-day moving average, which also stalled Monday’s intraday plunge of 10% triggered by US President Trump’s claim of a new round of negotiations between the US and Iran.

Watch the $88.36/85.50 key short-term pivotal support, and a clearance with an hourly close above $93.70 may see a further push up to retest the minor range resistance of $102.25 (see Fig. 5).

An analysis of the current price structures of the related cross asset classes, S&P 500, US Dollar Index, AUD/USD, and West Texas crude oil, suggests that we are not out of the woods yet for a significant bullish reversal in risk appetite to take form.

Perhaps the market is rebuking US President Trump’s claims of an imminent ceasefire between the US, Israel, and Iran.