Key Takeaways: Japan's equity market carries more embedded leverage and concentrated positioning than before the August 2024 crash that wiped 24% off the TOPIX.
Key Takeaways: Japan's equity market carries more embedded leverage and concentrated positioning than before the August 2024 crash that wiped 24% off the TOPIX.

Japan's equity market carries more embedded leverage and concentrated positioning than before the August 2024 crash that wiped 24% off the TOPIX.
The TOPIX faces higher structural vulnerability than before its 24% crash in August 2024, with foreign net positions exceeding pre-crash levels by more than 20%, according to Goldman Sachs Group Inc.
"The probability of a yen-triggered flash crash is lower this time, but the market's fragility is higher because positioning is more extreme and concentrated," said Bruce Kirk, chief Japan equity strategist at Goldman Sachs.
Foreign investors have poured about 14.8 trillion yen ($97 billion) into Japanese stocks since April, pushing net holdings more than 20% above July 2024 levels. Hedge fund allocation to Japan sits at the 99th percentile of the past five years, while retail margin debt has climbed 35% above pre-crash levels to near five-year highs, Goldman's prime brokerage data show. The Nikkei 225 and TOPIX have surged 53% and 37% respectively since July 11, 2024.
The concentration risk echoes the 2024 crash mechanism, when an 11% yen surge in three weeks triggered forced liquidation across crowded long-exporter and long-financial positions. This time, the crowded trade is AI-related exporters and banks — and any shock to the AI narrative or a geopolitical event could set off a similar cascade, Kirk said.
The structural parallels to 2024 are striking. Before the August crash, the market carried an implicit long bias toward exporters and financials against short domestic defensives. Today, that same skew has reemerged with greater intensity: the Nikkei/TOPIX ratio has widened to 18 times, a historic extreme, while AI-related stocks trade at a median valuation nearly double that of non-AI names. Many TOPIX constituents still trade below their 200-day moving average, yet the index is driven higher by a narrow cluster of banking, metals, electronics and AI-linked exporters.
The 2024 crash unfolded in two phases. From July 11 through month-end, a softer US CPI print and yen intervention hit exporter stocks first, while bank shares rose 5% on the Bank of Japan's July 31 rate hike. The real carnage came in the next five sessions: the BOJ's hawkish surprise combined with a weak US July payrolls report on Aug. 2, sending bank stocks down 27% from their post-hike peak. Multi-strategy hedge funds with drawdown limits around 2.5% of deployed capital saw market-neutral portfolios suffer peak-to-trough losses of about 5% — enough to trigger stop-losses, forced deleveraging and a cascade that swept in risk-parity and trend-following strategies.
The Yen Factor Has Changed
The macro backdrop for the yen is fundamentally different from 2024. Goldman's G10 FX strategy team has raised its USD/JPY forecasts to 162, 163 and 165 for three, six and 12 months respectively, from 160, 158 and 155 previously, citing higher-for-longer US rates, low recession risk, Japan's fiscal concerns and an extremely gradual BOJ hiking path. The 10-year Japanese government bond yield has approached 3%, driven by a widening term premium tied to fiscal sustainability worries rather than narrowing US-Japan rate differentials.
The risk, however, is that the market has priced none of this for a sudden yen reversal. One-month implied volatility in USD/JPY remains relatively low, meaning a rapid strengthening — even if less probable than in 2024 — would catch positioning off guard. CFTC data show speculative short yen positions have rebuilt to near July 2024 levels, but the market is now pricing persistent yen weakness, whereas the 2024 crash was triggered by a move the market had not priced at all.
Two Tail Risks to Watch
Kirk identified two scenarios that could upend the current setup. The first is a shock to the global AI narrative — an event similar to the DeepSeek-driven selloff in early 2025 that would hit the concentrated AI-related positions dominating the TOPIX. The second is a geopolitical shock that undermines US-led global growth stability, simultaneously pressuring the export-heavy sectors where foreign and retail investors are most exposed.
"Two years ago, many overseas investors characterized the crash as a Japan-specific problem," Kirk said. "Today, Japan's equity market is carrying a concentrated expression of the global AI theme. If that narrative reverses, the unwind won't stay in Japan."
This article is for informational purposes only and does not constitute investment advice.