The Session: A Violent Morning, a Quiet Close
The Nikkei 225 finished Monday, August 31 at 66,311.93, down just 0.14% — a closing number that hides one of the rougher intraday rides in recent weeks. The index plunged more than 1,500 points in the morning, nearly 2%, to an intraday low of 65,096.63 before heavy afternoon dip-buying erased almost the entire loss. The broader TOPIX did better still, finishing in positive territory — up 0.35% by our 1306 ETF proxy — as money rotated out of chip names and into banks, utilities and value. Total TSE turnover was a hefty JPY 10.41 trillion.
The morning damage came from a familiar trio: rising long-term bond yields at home and abroad, hawkish signals from U.S. Fed Chair Kevin Warsh, and reported strikes near the Strait of Hormuz. Friday’s Wall Street tech sell-off set the tone — the S&P 500 closed 0.25% lower at 7,711.76 — but supportive domestic industrial production and retail sales readings helped the afternoon recovery. The yen offered no relief either way, weakening roughly 0.2% as the dollar rose to around 159.6 yen, still hovering near multi-decade lows.
Sectors and Movers
By TOPIX-17 ETF proxies (Nomura NEXT FUNDS closes, which can deviate slightly from official sector indices), 8 of 17 sectors advanced. Power & Gas led at +2.89%, Energy Resources gained 2.05% on the Hormuz headlines, and Banks rose 1.77% — extending a 5.6% run over five sessions as rate-hike expectations build. Pharmaceuticals (-1.32%), Machinery (-1.25%) and Real Estate (-0.89%) lagged.
Among the 95 large caps we track (a fixed universe, not a full-market scan):
| Gainers | Losers |
|---|---|
| Kubota +3.75% (volume 2.2x 20d avg) | Advantest -4.48% |
| Suzuki +2.63% | Mitsubishi Heavy -3.38% |
| Nissan +2.34% | IHI -3.04% |
| Recruit +2.33% | Lasertec -2.89% |
| NTT +2.31% | Daiichi Sankyo -2.83% |
Advantest was the day’s headline casualty, tracking Friday’s steep drop in the Philadelphia Semiconductor Index and sliding as much as 7% intraday before closing down 4.48% at 33,690. Tokyo Electron, notably, clawed all the way back to close up 0.37% at 56,440 — a telling divergence within the chip complex. Elsewhere among the megacaps, Sony gained 2.24%, Fast Retailing 1.67%, Toyota 1.28%, SoftBank Group 0.76%, and MUFG 0.60%.
Rates and the Yen: The September Question
JGB yields keep grinding higher. As of Friday’s MOF close (August 28), the 10-year stood at 2.930% (+3.3bp on the day), the 30-year at 4.084% (+4.6bp), and even the 2-year at 1.719%. Markets are increasingly pricing a potential rate hike at the BOJ’s September 16-17 policy meeting, aimed at countering yen weakness and domestic inflation. With USD/JPY around 159.6, the pressure on the central bank is not subtle.
Positioning: The Daily Short-Sell Read
Monday’s TSE short-selling ratio — our daily positioning signature — came in at 42.3% of total trading value (34.9% price-rule restricted plus 7.4% unrestricted). That sits in the middle third of the last eight sessions’ 39.1%-45.9% range, right around the 43.0% average: defensive by long-run standards, but not a fresh extreme despite the morning scare. The Nikkei Volatility Index told a sharper story, jumping 4.58 points to 27.83 — the 74th percentile of the last 895 sessions, elevated but still within normal bounds.
Friday’s JSF standardized-margin data (the latest available; Monday’s is not yet published) showed leveraged long demand of JPY 0.67 trillion against JPY 0.25 trillion of stock lending on the short side. The single-name detail is interesting: shares borrowed for shorting jumped in Toyota (+54,400 on the day) and Sony (+45,100) — fresh shorts leaning into strength — while Advantest saw leveraged longs cut sharply (margin-loan balance -59,600 shares) ahead of Monday’s drop. Premium charges (gyaku-hibu, the extra daily cost short sellers pay) applied to 588 of 1,150 loanable issues, or 51% — broad squeeze pressure. JSF also suspended new short applications in the Nikkei double-inverse ETF (1366) on August 26.
In the lagged regulatory filings published Monday, disclosed short positions of 0.5% or more covered 615 issues; Sanrio’s aggregate disclosed short rose 2.69 percentage points to 12.4% — positioning data reported with a delay, not a driver of today’s move.
Weekly Flows
For the week of August 17-21 (JPX data published with a lag — these are not today’s flows), foreign investors were net buyers of JPY 0.21 trillion of TSE Prime equities while individuals net sold JPY 0.64 trillion. One caveat worth flagging: MOF’s cross-border securities data for roughly the same week, compiled on a different reporting basis, showed foreigners as net sellers of JPY 0.76 trillion — a directional conflict that argues for treating the foreign-flow picture as unresolved until next week’s figures. Meanwhile the broader Tokyo+Nagoya margin balances (as of August 21) showed margin buying at JPY 6.48 trillion, up 0.28 trillion on the week, against just 0.90 trillion of margin selling — retail leverage continues to build.
What to Watch
- JGB yields into the BOJ’s September 16-17 meeting. With the 10-year at 2.930% and the yen near 160, rate expectations are now the market’s dominant macro input.
- Semiconductor follow-through. Tokyo Electron’s full intraday recovery versus Advantest’s 4.48% loss suggests the chip sell-off is discriminating, not indiscriminate. Tonight’s U.S. session (S&P futures last at 7,710, -0.16%) sets the tone.
- The foreign-flow divergence. JPX shows foreigners buying, MOF shows them selling for the same week — next week’s data should clarify who is actually on the bid.
Disclaimer: This is an information and analysis publication, not investment advice. See our Methodology for data sources, standards, and our corrections policy.