Goldman Sachs Exchanges
2026-08-17 · Hosted by Allison Nathan · Goldman Sachs
Executive Summary
Japan and the US conducted their largest coordinated currency intervention in 15 years starting July 30, with Japan's Ministry of Finance selling an estimated $85 billion to buy yen over two days -- the biggest two-day intervention on record outside the 2011 Fukushima response. Goldman's Karen Fishman and Praneet Shah joined host Allison Nathan to explain why: the yen had hit 40-year lows versus the dollar, driven by Japan's inflationary policy mix (big government spending paired with only gradual Bank of Japan rate hikes) and a low-volatility global backdrop that favored carry trades against the yen.
Key Stories & Changes
1. Coordinated US-Japan FX Intervention
Japan's MOF intervened July 30-31, an estimated $85 billion, with possibly more on August 3rd
Biggest two-day Japanese FX intervention on record outside October 2011 (Fukushima aftermath)
First coordinated US-Japan action since 2011; that prior episode was coordinated across the full G7
Trading-floor detail: MOF sold roughly $60 billion Thursday, $25 billion Friday, possibly $20 billion more Monday, versus a normal ~$30 billion average daily volume
EBS spot exchange volumes hit $90 billion Thursday, $80 billion Friday versus a typical $5-10 billion/day
Dollar-yen moved 3% on the MOF action, then another 2% once US coordination signals emerged -- despite the US leg being "significantly less" in size (historically $1-2 billion for the US in coordinated interventions)
Dollar-yen breached the 158 200-day moving average, a key technical/psychological level
2. Why the Yen Was Weak and Why It Matters
Japan's fiscal spending plans plus only gradual BOJ hikes have been read by markets as inflationary, pushing real returns down and capital abroad
No corresponding rise in recession odds or safe-haven demand this year, plus persistently low FX volatility, created ideal conditions for carry trades against the yen
A weaker yen raises import costs (groceries, gas, electricity, travel) and government borrowing costs, though it benefits exporters and inbound tourism
Yen has depreciated 45% over five years, an 8% compounded annual pace
3. Why the US Joined In
Goldman's Fishman argues US involvement is more about US market functioning than a strong view on yen levels, for three reasons:
Debate remains whether this could undermine dollar reserve-currency appeal; Goldman's view: it doesn't, and the Fed facility's availability actually reinforces the dollar's unmatched network effects
4. Trading Floor Dynamics and Positioning
Initial flow was leveraged accounts (hedge funds, CTAs) cutting long-dollar-yen carry positions once the 158 level broke, wiping out annualized carry (2-2.5%) in a single move
Fourth-largest absolute reduction in yen positioning in the 20-year CFTC history
Clients showed more interest in Euro-yen than dollar-yen this cycle; 187.50 was the key trigger level (also the level that sparked the April-May intervention)
Client flow has been split: roughly half playing for continued yen strength (targeting 150 in dollar-yen, a 5% Euro-yen move) and half buying the dip, viewing nothing as structurally changed
Options market still shows elevated risk premium in 2-week to 1-month yen call options, signaling the market still fears a sharp yen move
MOF Thu+Fri intervention: ~$85B
EBS spot volume (Thu/Fri): $90B / $80B
Dollar-yen move (initial): -3%
Dollar-yen move (post-US signal): additional -2%
Key technical level: 158 (200-day MA)
September BOJ hike odds: 65%
Trends Identified
1. Intervention Buys Time, Not a Structural Fix
Goldman's Fishman was explicit: intervention alone is not sustainable and historically only delays yen weakness unless followed by real policy change. The same playbook (April-May 2026) saw the yen back at 40-year lows within months. The market now hinges on whether the BOJ actually delivers a September hike -- failure to do so would renew downward pressure.
2. Valuation Undervaluation Could Support Structural Yen Strength
Beyond the near-term momentum trade, Goldman flagged the yen as roughly **25% undervalued** (undervalued means priced below its estimated long-term fair value) on long-term models, with 10-year JGBs now offering 100 basis points of extra currency-hedged yield over 10-year Treasuries. If Japanese investors reverse a decade-long shift toward foreign assets, that could be a more durable source of yen appreciation -- though officials would need to make domestic assets more attractive first.
3. Market Function, Not FX Level Targeting, Drives US Policy
The pattern of US involvement lining up with periods of US rate volatility -- rather than a fixed view on where the yen "should" trade -- suggests Washington's FX intervention calculus is really about US Treasury market stability, a distinct motivation from Tokyo's currency-stability goal.
4. Dollar Outlook Diverges by Currency Pair
Goldman's baseline dollar view is for continued modest strength against low-yielding currencies like the euro, but continued dollar weakness against the yen specifically -- a nuanced, not uniformly bearish or bullish, dollar call for the back half of the year. ---
Sentiment Analysis
Overall Market Sentiment: Cautiously Constructive on Yen
Guests see intervention as effective at stabilizing rather than reversing yen weakness, with medium-term upside contingent on BOJ follow-through and possible structural shifts in Japanese investor behavior.
Risk Factors Highlighted
BOJ fails to hike in September: Would renew downward pressure on the yen after the intervention's stabilizing effect fades.
Intervention fatigue without policy follow-through: History (April-May episode) shows unilateral intervention alone reverses within months.
Elevated options risk premium: Two-week to one-month yen call options still price a meaningful chance of a sharp gap move lower in dollar-yen.
US Treasury market spillover: A weaker, more volatile yen risks a stronger, more volatile dollar, raising broader financial stability concerns.
Reserve-currency perception risk: Unconventional policy tools (like the Fed's swap facility) could, in a more extreme scenario, raise questions about institutional reliability, even though Goldman downplays this risk currently.
Global growth/AI-related shocks: A broader risk-off event tied to AI or growth concerns could increase safe-haven yen demand independent of BOJ action.
Structural carry-trade unwind risk: Persistent low FX volatility has encouraged heavy carry positioning that could unwind abruptly again, as seen in this episode.
This episode was covered in today's [The Market Signal — 2026-08-17](https://marketsignal.beehiiv.com/p/the-market-signal-2026-08-17), a cross-source synthesis of multiple podcast reports.