The US dollar declined Friday, September 25, as oil prices eased, while the Japanese yen rallied sharply after Japan said Tokyo and Washington remain committed to the currency-support stance behind July's joint intervention.

Why the Dollar Pulled Back

The dollar was on track to snap a four-day streak of gains as crude prices slumped more than 2%. Global oil prices eased as the potential for a truce between the US and Iran outweighed supply concerns tied to increasing Houthi attacks against Saudi Arabia. Even with the pullback, oil remained above $100 a barrel, continuing to exert upward pressure on inflation. Despite Friday's dip, the dollar was still on pace for a second straight weekly advance, supported by growing bets on further Fed rate hikes.

Why the Yen Jumped

The yen strengthened 1.06% — its biggest daily gain against the dollar since September 7 — trading around 157.13, on pace to snap a four-day streak of declines. The rally followed comments from Japan's Finance Minister Satsuki Katayama, who said President Donald Trump raised concern about yen weakness during a summit with Japanese Prime Minister Sanae Takaichi earlier in the week — with Katayama noting Takaichi replied that an undervalued yen was problematic "as a general principle." Katayama and Treasury Secretary Scott Bessent held a call Friday, reaffirming that yen undervaluation remains a matter of concern and that the two nations intend to strengthen cooperation, according to a statement from Japan's Finance Ministry.

The Yen's Still Facing Headwinds

Despite Friday's sharp rally, the yen remained on track for a second straight weekly fall, after markets judged the Bank of Japan's rate hike last week — which took rates to a 31-year high — and its accompanying guidance as insufficiently hawkish to durably support the currency. USDJPY had fallen back below its 200-hour moving average and 50% retracement level near 158.45, with technical analysts noting sellers retained control while the pair stayed below that threshold.

Why the Fed Is Driving Dollar Strength Elsewhere

Comments from central bank officials flagging inflation concerns and support for further rate increases — following last week's 25-basis-point hike — have boosted market expectations for a more aggressive Fed tightening path, sparking a jump in US Treasury yields. Eugene Epstein, head of trading and structured products at Moneycorp in Stamford, Connecticut, offered a measured read on Friday's pullback: "We've had like a pretty aggressive rally in the dollar over the last couple of days and maybe it's a little stretched, just taking a little breather. So I wouldn't really say that the dollar is really weakening materially today." He attributed the moves to a combination of slightly higher odds of a second hike before year-end and broader concern over rising bond yields.

Sterling Also Gained

The British pound strengthened 0.23% to $1.3246, supported by hawkish comments from Bank of England Governor Andrew Bailey, though it remained close to a three-month low hit on Thursday.

The Bigger Picture

Friday's session illustrates how tightly currency markets remain tethered to two parallel storylines: the ongoing US-Iran diplomatic and oil-price dynamics, and the deepening US-Japan cooperation on managing yen weakness. With both threads still actively developing, currency traders are likely to remain highly reactive to fresh headlines on either front in the sessions ahead. For live currency market data, see Reuters Currencies.