The Dax initially started the new week with significant losses and investors were nervous about the situation escalating Iran war impressively reflected. But just a few hours later came the surprising turnaround US President Donald Trump: He postponed his ultimatum against Iran by five days and initially did not promise any attacks on energy facilities – again with immediate consequences for the markets.

On Monday morning, the leading German index temporarily fell by 1.87 percent to 21,961 points. This meant that it slipped below the 22,000 point mark for the first time since the “customs shock” in April 2025.

The second row also came under pressure: the MDax lost 2.34 percent to 27,145 points in the morning, while the EuroStoxx 50 fell by 1.6 percent. In Asia the discounts were sometimes even more significant. The trigger was the renewed escalation in the conflict between the USA and Iran.

Iran counters Trump: Markets react nervously

At the beginning of the week, the situation initially deteriorated further. According to media reports, Tehran responded to US President Donald Trump’s ultimatum with sharp countermeasures and threats.

On Sunday night, Trump demanded that Iran… the Strait of Hormuz within 48 hours should open completely – otherwise there would be a risk of central energy systems being destroyed. The Iranian leadership then again announced a complete blockade of the strategically important strait.

The Strait of Hormuz is a critical point for markets: around a fifth of global oil trade passes through this route. Risk aversion and uncertainty rose correspondingly quickly.

Sudden U-turn: Trump postpones ultimatum

But around midday Central European time there was a surprising turn of events. Within a few minutes, the news spread that Trump was postponing his ultimatum by five days and that no attacks on Iranian energy facilities were planned for the time being. The background is said to have been diplomatic signals and international mediation efforts.

The reaction on the markets was exceptionally strong. The Dax jumped by over 1000 points within a very short time. The index briefly rises above 23,000 points again. It was one of the strongest intraday moves in recent years. Such swings within a very short period of time are unusual, even in volatile market phases.

In parallel with the DAX rally, the price of oil fell significantly. The price of Brent crude oil fell noticeably after geopolitical risk premiums had been priced in.

Between euphoria and reality: the situation on the stock market remains fragile

Despite the strong countermovement, market developments warn against hasty conclusions. Relaxation is based on one thing temporary political decision.

The structural risks in the Middle East remain and the conflict is by no means resolved.

The DAX itself showed this uncertainty again on Monday: After the price jump, the index fell again and is currently around one percent below its interim high. The market is roughly fluctuating between around 22,700 and 23,200 points and is clearly looking for a stable valuation level.

Market timing is extremely difficult for investors

Recent market movements highlight key mechanisms that are particularly relevant for long-term investors.

First The speed with which prices react to new information has increased significantly: market swings now often occur within a few minutes, making it virtually impossible for private investors to react consistently.

Second shows once again how difficult reliable market timing is. Anyone who exits the market during periods of increased uncertainty runs the risk of missing out on the often strong countermovements that follow.

Third Such episodes underline the empirically well-documented finding that a long-term investment strategy is generally more successful than short-term tactical interventions. Time in the market has a greater impact on investment success than attempting to optimize entry and exit times.

Fourth It becomes clear that emotional decisions remain a significant risk factor: sales based on fear often lead to suboptimal timing and can have a lasting impact on returns.

The bottom line is that the current development is a sign of short-term relaxation – nothing more, but also nothing less. Markets are extremely sensitive to geopolitical news and this dynamic is likely to continue.