The US dollar posted its sharpest single-session decline in more than a month after President Donald Trump signaled that talks with Iran were making meaningful progress. The announcement flipped a switch in global markets, pulling capital away from safe-haven assets and into riskier corners of the financial universe, including crypto.

The dollar index dropped to approximately 98.9, marking a notable retreat that caught the attention of forex traders and crypto investors alike.

What happened and why it matters

Trump’s comments around late May pointed to tangible progress in negotiations with Iran, a development that immediately dampened demand for the dollar. Geopolitical tension typically drives investors toward safe havens like the greenback and US Treasuries. Remove that tension, even partially, and the trade unwinds.

Oil prices also softened on the prospect that the Strait of Hormuz, one of the world’s most critical chokepoints for energy supply, could see reduced risk. Risk-on sentiment surged across asset classes. Bitcoin and Ether both posted gains exceeding 3% during certain trading sessions as the broader crypto market cap rebounded by an estimated $75 billion following the positive Iran-related news.

The crypto connection

Bitcoin had been trading near two-week lows around $76,500 before the Iran deal optimism kicked in, with the price recovering into the $76K to $78K range as sentiment improved.

Earlier in 2026, US sanctions targeted approximately $344 million in crypto wallets linked to Iran. So the same geopolitical conflict driving dollar movements was already directly entangled with the crypto ecosystem. Any progress on a deal could reshape how enforcement and compliance play out in the digital asset space.

What this means for investors

For forex traders, the move signals that geopolitical developments are currently dominating monetary policy expectations as a driver of dollar direction. When a diplomatic announcement can trigger the biggest dollar selloff in over a month, the playbook changes.

The positive correlation between de-escalation news and crypto rallies means that further progress in Iran talks could sustain upward momentum. But correlations cut both ways. If negotiations collapse or tensions flare again, the same mechanism that pushed Bitcoin higher could slam it back down just as fast.