The US dollar is expected to record its largest single-day rise in a month.

According to foreign media reports, the U.S. dollar is expected to record its biggest one-day gain in a month on Friday as investors re-bought the U.S. dollar after Israel’s attack on Iran, triggering Iran’s retaliation. At first, the safe-haven currencies Swiss franc and the Japanese yen rallied, but then they were recovered by the US dollar. The U.S. dollar has always been the ultimate safe haven in times of geopolitical or financial turmoil. The U.S. dollar rose nearly 0.9% against a basket of major currencies, with the euro, pound sterling and Australian dollar falling particularly sharply. The U.S. dollar index rose 0.85% and is on track for its biggest one-day gain since May 12. Fiona Cincotta, strategist at City Index, said the dollar is returning to its traditional safe-haven role, although the boost may not last long if the situation eases somewhat over the weekend.