Yen gains as Trump rules out Iran strikes: what a safe-haven currency is

The Japanese yen gained late on Thursday after President Trump said the US would not attack Iran before the midterm elections, FXStreet reports. The same report says the 10-year Treasury yield ended near 5.22%, after touching its highest level since 2002 on Wednesday.

The yen was not the only winner. In a separate story, FXStreet says safe-haven flows shifted from the US dollar to the yen and the Swiss franc as Wall Street fell, while the Australian dollar slipped 0.11%. The geopolitical picture stayed unsettled. investingLive relayed unverified reports of explosions in the Strait of Hormuz, and FXStreet, citing the New York Times, says Trump ordered plans for possible renewed strikes even while ruling them out before November 3. Our sister site covers the dollar side in how the dollar eased as Trump ruled out Iran strikes.

What is a safe-haven currency?

A safe-haven currency is one that investors tend to buy when they feel nervous. Fear can come from war, a stock market fall or a financial crisis. In those moments, many traders sell riskier assets and park money somewhere they see as stable.

The yen, the Swiss franc and the US dollar are the usual examples. Gold plays a similar role outside currencies. FXStreet reports gold edged up to around $4,140 early on Friday in Asia.

The opposite group is often called risk currencies. The Australian dollar is a common example. It tends to weaken when markets are fearful, as Thursday's Aussie dip showed.

One point confuses beginners. Safe havens can compete with each other. On Thursday, FXStreet says money moved out of the dollar and into the yen and franc. So a "safe-haven day" does not always mean the dollar rises.

A worked example

We use the official ECB reference rates, or fixings. The ECB publishes one per business day. They are not live quotes. The latest are from 8 October 2026, compared with 7 October.

USD/JPY tells you how many yen buy one dollar. If the yen strengthens, this number falls.

1. At the 7 October fixing, $10,000 bought 10,000 × 158.23 = 1,582,300 yen.
2. At the 8 October fixing, it bought 10,000 × 158.28 = 1,582,800 yen.
3. That is 500 yen more, so the yen was slightly weaker at the fixing.

The same sum in francs went from 8,329 to 8,337, also 8 francs more per $10,000.

Why does this not match the "yen gains" headline? Timing. The fixing is taken during the European day. Trump's comments and the yen's gains came later, in US trading, according to FXStreet. A once-a-day reference rate cannot show a move that happened after it was set. You can follow intraday moves on a live chart such as USD/JPY on TradingView or USD/CHF on TradingView.

The Aussie fixing tells a cleaner story. AUD/USD fell from 0.6951 to 0.6943, a drop of 0.0008, or 8 pips. That fits the risk-currency pattern.

Why it matters for new traders

Safe-haven flows can move currencies even when economic data is quiet. A headline about war or a sharp stock sell-off can matter more than a scheduled release.

The effect is not fixed. On a given day the dollar may gain as a haven, or lose to the yen and franc, as FXStreet describes for Thursday. Rising US yields can also pull money into the dollar for different reasons. Read the driver behind the move, not just the label.

Finally, check your timestamps. A daily fixing and a live chart can tell different stories about the same day.

Key terms

• Safe-haven currency: a currency investors buy in times of fear, such as the yen or Swiss franc.
• Risk currency: a currency that tends to fall when markets are nervous, such as the Australian dollar.
• Safe-haven flows: money moving into perceived safe assets during stress.
• Fixing (reference rate): an official once-a-day exchange rate, here from the ECB.
• Treasury yield: the return on US government bonds, which can influence the dollar.