〔Overnight Brief〕Yen's 1.76% Surge Puts 155 Short-Covering Trigger in Play as 30-Year JGB Auction Beats; ECB 'Final Hike' to 2.50% Seen Sept. 10 - Budget-Rate and Gold-Move Warnings Keep Long-End Risk Alive

0. Weekly Arc

The overnight session was a global bond breather, not a full unwind ^[1]. Tokyo anchored the move: the yen jumped 1.76% on the day and a strong 30-year JGB auction pulled yields from historic peaks ^[2][3]. Yet the fiscal-credit worry is unresolved - Japan's budget-interest-rate assumption of 3.8%, a 30-year high, keeps the long end exposed ^[4]. In Europe, the ECB's Sept. 10 meeting is the clearing event, with all 65 surveyed economists expecting a 'final' 25bp hike, while futures price more ^[5]. German institutes simultaneously lifted their 2026 growth forecasts ^[6].

1. Yen: Intervention, Hike and the FSA

• The yen reached 155.91 per dollar, up 1.76% - its best daily performance since the Tokyo-Washington joint intervention about a month earlier ^[2]. Reuters described it as heading for its biggest two-day rally since that official boost ^[3].
• Finance Minister Satsuki Katayama and Treasury Secretary Scott Bessent both said they would 'not hesitate' to intervene again if needed ^[2].
• JPMorgan sees short-covering accelerating further yen gains if the appreciation breaks through 155 ^[7].
• The BOJ is leaning toward a 25bp September hike, cooling expectations for a larger step; board member Hajime Takata said a 25bp rise was not a foregone conclusion ^[2].
• Japan's Financial Services Agency will strengthen its inspections of banks' overseas branches ^[8].
• The 30-year JGB auction drew a 3.79 bid-to-cover ratio versus a 3.52 twelve-month average, beating the soft-to-moderate expectations ^[2].
• At the G20, Bundesbank President Joachim Nagel said the U.S. should have coordinated with European partners before selling euros to support the yen, prompting U.S. complaints to Berlin ^[9].

2. ECB: A 'Final' Hike and Succession Chess

• All 65 economists in the Reuters survey expect the ECB to deliver a 25bp hike on Sept. 10, lifting the deposit rate to 2.50% ^[5].
• About 91% see rates staying at 2.50% through the end of the year; 78% expect that plateau at least until mid-2027 ^[5].
• Economists expect the cycle to end at two hikes - the shortest since 2011 - while rate futures price a third increase ^[5].
• Euro-area bond yields declined, with Germany's 2-year yield down 5.1bp at 2.932% ^[10].
• German Chancellor Friedrich Merz will attend the Bundesbank dinner in Berlin next week, where the ECB will also hold its policy meeting ^[11].
• Germany is weighing Bundesbank President Joachim Nagel for the ECB presidency, backed by Finance Minister Lars Klingbeil; ECB board member Isabel Schnabel is meanwhile in talks with the IMF for the monetary and capital markets department, which could cut her from the race and narrow Germany's field ^[11].
• ECB President Christine Lagarde's term runs until October 2027, but she has not denied leaving early, while the World Economic Forum is courting her as its next chair ^[11].

3. Currency and Fixed-Income Crosscurrents

• In the New York session, non-dollar currencies were broadly bid: EUR/USD added 0.35% to 1.1629, GBP/USD rose 0.29% to 1.3528, and USD/CHF fell 0.67% to 0.8074 ^[12].
• The forint was the standout gainer at +1.9%, followed by the Swedish krona at +0.98% and the Polish zloty at +0.56%, while the Mexican peso and Brazilian real each weakened modestly against the dollar ^[12].
• Australia's bonds have seen yields rise more than any peer's over the past month, despite arguments that the country's finances are in better shape ^[13].
• European markets rose as the fixed-income recovery took hold ^[14][1].
• Oil eased but stayed around $95 a barrel ^[3].

4. Fiscal-Credit and Safe-Haven Fragmentation

• Japan's new fiscal-year budget assumes a long-term interest rate of 3.8%, up from 3.0%, a 30-year high ^[4].
• A renewed yen intervention could push U.S. long-end yields higher, with the 30-year Treasury yield potentially probing 5.5% or beyond ^[4].
• Central banks are already shifting physical gold to diversify against dollar-credit revaluation ^[4]. The Dutch central bank cut its U.S.-held gold reserves, citing 'geopolitical unrest'; President Olaf Sleijpen said, 'We have improved the tradeability of our gold reserves' ^[15].
• Israel's war economy is splitting: the Bank of Israel estimates 2023-2026 fiscal costs around 350 billion shekels, pushing public debt to 68.5% of GDP at end-2025 from roughly 60% before the war, while 2025 tech financing and defense exports hit records ^[16].
• Germany's research institutes raised forecasts: Ifo sees 2026 GDP at +1.4%, up from 0.8%, and Kiel and Leibniz each see +1.3% ^[6].
• Korea's unadjusted current account narrowed to $42.08 billion in July from $49.73 billion in the previous month ^[17].

5. Trade, International Politics and EM Signals

• Canadian Prime Minister Mark Carney said Canada is ready to negotiate a trade deal 'as long as the U.S. is ready,' but any agreement must preserve the competitiveness of Canadian autos, steel and aluminum and provide stable tariff treatment ^[18]. U.S. President Donald Trump responded that treating him as an enemy could lead to a 'collapsed Canadian economy' ^[18].
• A Reuters poll shows analysts raised Canadian-dollar forecasts, expecting trade tensions to ultimately fade ^[19].
• The U.S.-German rift at the G20 was not limited to the central-bank FX criticism: Treasury Secretary Scott Bessent was also displeased with Finance Minister Lars Klingbeil's uncompromising public stance toward Russia ^[9].
• IMF staff will visit Sri Lanka from Sept. 10 to 23 ^[20], and the IMF urged Norway to move its budget stance to neutral in order to curb price pressures ^[21].