Key Takeaways
- • Benchmark volatility for "Kabu Opt" market-making eligible stocks declined materially as of August 14, 2026: mean volatility fell to 40.06% (down from 44.88% week-over-week), while median volatility dropped to 32.92% (down from 37.91%), indicating a softening volatility environment across the eligible stock universe.
- • AI7 stocks remain significantly more volatile than other eligible securities: the seven AI-focused stocks averaged 75.89% implied volatility compared to 34.36% for the remaining 44 eligible stocks—a 41.53 percentage point spread—though this gap narrowed as AI7 benchmark volatility fell 12.11 percentage points week-over-week.
- • Volatility distribution has widened, signaling skewed market conditions: the gap between mean and median volatility expanded to 7.14 percentage points from 6.97 percentage points, suggesting concentration of volatility risk in select stocks rather than broad-based distribution.
- • AI7 stocks' contribution to overall benchmark volatility declined modestly: the contribution rate fell approximately 1 percentage point to 14.23% from 15.28%, indicating slightly diminished relative impact despite maintaining substantially higher volatility levels than the broader cohort.
- • Minor shifts in top-ranked volatility stocks observed: while leadership remained stable with Fujikura retaining the #1 position, mid-tier rankings showed movement—notably Murata Manufacturing rising to #2 and Lasertec dropping to #5—reflecting tactical rebalancing within the market-making eligible universe.
Summary
The benchmark volatility snapshot for "Kabu Opt" market-making eligible stocks as of August 14, 2026, reveals a moderating volatility environment driven primarily by sharply lower implied volatility in AI-exposed securities. Both headline volatility metrics contracted week-over-week: mean volatility declined 4.82 percentage points to 40.06%, while median volatility fell 4.99 percentage points to 32.92%. This synchronized contraction across both measures indicates genuine softening in the eligible stock universe rather than isolated moves in outlier positions.
However, the volatility distribution has become increasingly skewed, with the mean-median spread widening to 7.14 percentage points from 6.97 percentage points. This expansion signals that volatility is concentrating in a subset of higher-volatility names, with the overall benchmark pulled upward by outsized moves in specific securities rather than broad-based repricing. The reference volatility framework tracks at-the-money implied volatility for eligible market-making stocks, with data sourced from the Japan Exchange Group (JPX).
The most pronounced volatility dynamic remains the persistent gap between the AI7 stocks and the remaining 44 eligible securities. The seven AI-focused stocks exhibited average implied volatility of 75.89%—down 12.11 percentage points from the prior week's 88.00%—while the broader 44-stock cohort averaged 34.36%, a decline of 3.66 percentage points from 38.02%. This 41.53 percentage point differential underscores the sector-specific volatility premium embedded in AI equities, though the week-over-week contraction was substantially sharper for AI names, suggesting partial repricing or reduced hedging demand in that segment.
The contribution rate of AI7 stocks to overall benchmark volatility declined approximately 1 percentage point to 14.23% from 15.28%, indicating that despite maintaining elevated absolute volatility levels, the AI-focused cohort's marginal impact on the headline benchmark has moderated. Ranking shifts within the top eight stocks reflected minor tactical adjustments: Fujikura retained the #1 position, while Murata Manufacturing advanced to #2, and Lasertec retreated to #5. SoftBank Group (SBG), Advantest, and Recruit Holdings remained prominently positioned, confirming stability among the core market-making eligible universe despite incremental portfolio rebalancing.
However, the volatility distribution has become increasingly skewed, with the mean-median spread widening to 7.14 percentage points from 6.97 percentage points. This expansion signals that volatility is concentrating in a subset of higher-volatility names, with the overall benchmark pulled upward by outsized moves in specific securities rather than broad-based repricing. The reference volatility framework tracks at-the-money implied volatility for eligible market-making stocks, with data sourced from the Japan Exchange Group (JPX).
The most pronounced volatility dynamic remains the persistent gap between the AI7 stocks and the remaining 44 eligible securities. The seven AI-focused stocks exhibited average implied volatility of 75.89%—down 12.11 percentage points from the prior week's 88.00%—while the broader 44-stock cohort averaged 34.36%, a decline of 3.66 percentage points from 38.02%. This 41.53 percentage point differential underscores the sector-specific volatility premium embedded in AI equities, though the week-over-week contraction was substantially sharper for AI names, suggesting partial repricing or reduced hedging demand in that segment.
The contribution rate of AI7 stocks to overall benchmark volatility declined approximately 1 percentage point to 14.23% from 15.28%, indicating that despite maintaining elevated absolute volatility levels, the AI-focused cohort's marginal impact on the headline benchmark has moderated. Ranking shifts within the top eight stocks reflected minor tactical adjustments: Fujikura retained the #1 position, while Murata Manufacturing advanced to #2, and Lasertec retreated to #5. SoftBank Group (SBG), Advantest, and Recruit Holdings remained prominently positioned, confirming stability among the core market-making eligible universe despite incremental portfolio rebalancing.
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