The Stress Index Fell 0.371, the Largest One-Session Drop in This File. 0.326 of It Was the Price of Insurance.
Three different things are called credit. There is the spread - the extra yield a company pays over the government, which is the market's guess at whether it gets repaid. There is the all-in cost - the government yield plus that spread, which is what the borrower actually signs. And there is the stress gauge, which is a statistical average of a few inputs, two of which are not credit at all but the price of insurance on equities and on bonds. On Wednesday the gauge had its largest one-session drop in this file. The spreads, measured over the week rather than the session, went the other way. This column reads Thursday as credit and stress, so the question is which of the three is doing the talking, and what the other two would have to do to be proven wrong. Ahead: the exact decomposition of a 0.371 move, why the VIX is not a credit input, and the one number in investment grade that is 1 basis point from its own high.
The stress index had its largest one-session drop in this file
Credit & Stress is +0.350, from +0.721 the session before. The change is 0.371, and across the 43 daily snapshots from 10 September to today no session has produced a larger one. The prior worst was -0.260 on 18 September, itself an outlier; the third was -0.208 on 29 October, the day last week's column was written.
The sub-index is the average of four z-scores: high-yield OAS, investment-grade OAS, the VIX and the MOVE. Dividing each leg's change by four splits the 0.371 exactly. The VIX leg accounts for -0.241 and the MOVE for -0.085. High yield accounts for -0.022 and investment grade -0.023. The two volatility legs account for 88% of the move, and the two spread legs for 12%.
That split is the whole of today's argument and it is arithmetic, not interpretation. An index built out of four z-scores will move with whichever input has the largest standard deviation relative to its own history, and on a day the VIX falls 4.22 points the volatility leg dominates by construction. The gauge reported a collapse in stress. Two of its four inputs, the only two that measure whether a company can pay, moved by 0.045 between them.
The VIX fell 4.22 points, the most in the sample
The VIX is 16.61, from 20.83 - a fall of 4.22 points, or -20.3%. In rank terms it moved from the 22nd percentile of its own 3-year range to the 12th. The largest prior one-day fall in the 43 snapshots was 2.27 points, on 18 September.
The MOVE, which is the same idea applied to Treasury options, is 93.88 from 99.97. That is the third-largest one-day fall in the sample, behind 28 September and 7 October, and it puts rates volatility back at the 45th percentile.
The equity tape explains it. The S&P 500 closed at 7,688.62, up 119.70 points or 1.58% - the largest one-day gain in the sample, ahead of 22 September's 1.49%. The Nasdaq 100 added 0.91% to 28,437.17. Against the 29 October close the S&P is still 55.36 points lower.
Now the part that matters for a credit column. The VIX measures the price of protection on the S&P, and the MOVE measures the price of protection on Treasuries. Neither is a claim about a coupon. When both fall together on a day equities rally, what has been repriced is the demand for insurance - which is a real market signal, and a tradable one, but it is a signal about positioning, not about default. A gauge that treats it as a fourth of stress will read a collapse in hedging demand as a collapse in credit risk. That is the mechanical reason the index fell so far, and it is why the spread legs need to be read separately rather than netted against the VIX.
Over the week, spreads went the other way
High-yield OAS is 3.40% (FRED BAMLH0A0HYM2, as of 3 November), from 3.43% the print before. That is 3.0 basis points tighter on the session, which is what the gauge's -0.022 reflects.
Against 28 October the direction reverses. High yield was 3.14% on that date; it is 3.40% now, 26 basis points wider. Investment grade went from 0.86% to 0.93% (FRED BAMLC0A0CM, as of 3 November), 7 wider. Of the 26 basis points of high-yield widening, 19 are excess spread - high yield over investment grade, the part that is about default rather than about Treasury yields - and 7 are the base moving with it.
Last Thursday's column made the mirror-image calculation. Over the 3 sessions to 27 October, high yield tightened 22 basis points and 21 of the 22 were excess spread. The same 22 basis points have now been put back, and the composition is the same in reverse. The ratio of the two spreads is 3.66 from 3.65 a week ago - almost unchanged, because both legs widened together. This is not a high-yield event with investment grade standing still. It is the whole spread complex repricing.
Where the levels sit matters more than the direction. High yield at 3.40% is 51 basis points above its 1yr mean of 2.891%, in the 86th percentile of the 785 prints in the file, and 6 basis points off the 1yr high of 3.46% set on 30 March. Investment grade at 0.93% is 13 above its mean of 0.802% and in the 75th percentile. Neither market is tight. The session said stress was leaving; the level says the compensation for default risk is in the top quartile of the last year and rising.
The all-in cost rose for high yield and fell for investment grade
Add the base to the spread and the asymmetry becomes a number a treasurer would recognise. On 28 October the 10yr closed at 5.045% and high-yield OAS printed 3.14%, so the marginal high-yield borrower's reference cost was 8.19%. On the 4 November close and the 3 November print - the latest for each - those two add to 8.29%. That is +10.9 basis points.
The same arithmetic in investment grade gives the opposite answer. 5.045% plus 0.86% was 5.91%; 4.894% plus 0.93% is 5.82%, or -8.1 basis points. In one week the all-in cost of the riskier borrower rose and the safer borrower's fell. The 10yr fell 15.1 basis points over that week, and it did not reach high yield at all.
Where the 10yr's 15.1 basis points came from is the other half of it. Inflation compensation - the breakeven, the gap between the nominal 10yr and the inflation-protected one - went from 2.38% to 2.26% (FRED T10YIE, as of 4 November), -12.0 basis points. The real yield went from 2.665% to 2.634%, -3.1. So 12 of the 15.1 was the inflation leg and 3 was the real leg.
The breakeven at 2.26% is the lowest print since 13 August, when it was 2.24%. That is a meaningful disinflation signal and it belongs in a credit piece, because a fall in inflation compensation lowers the nominal rate a borrower pays without loosening anything real. The real yield - the part that actually has to be earned - is 2.634%, which is 3.1 basis points lower than a week ago and 83 basis points above the 1.8% anchor this model subtracts. The hurdle did not move. The inflation premium on top of it did.
Investment grade is 1 basis point from its 1yr high
Investment-grade OAS printed 0.94% on 16 March, the highest print in the 1yr window. It printed 0.94% on 30 October and again on 2 November, and it is 0.93% now. Last Thursday's column set 0.94% as the migration trigger: the level at which stress would be visible in better credits rather than in worse ones, which is a different and later stage of a credit cycle.
It reached the trigger twice inside 5 sessions without breaking it. That is a near-miss, and near-misses are informative. High yield widened 26 basis points over the week from a base of 3.14%; investment grade widened 7 from 0.86%. Relative to the level each started from, high yield moved 828% and investment grade 814% - the same repricing seen at two notches of quality.
The stress index cannot see this. Its investment-grade leg is 0.488, which is a z-score of the level against the file's own mean. A z-score of 0.488 reads as moderate. A spread 1 basis point from a 1yr high reads as late-cycle. Both descriptions are of the same print, and the second is the one a portfolio manager acts on.
This is the reason the migration case stays open. The confirming failure would be a print at or above 0.95% with high yield holding above 3.40%. The refutation is a print back at 0.90% or below with high yield at or below 3.14%. Everything between is the market deciding, and it has been deciding for 5 sessions.
Secured funding fixed 7 basis points above administered
SOFR is 3.97% (NY Fed, as of 3 November) against an administered rate of 3.90% (FRED IORB, as of 4 November and unchanged through the 5 November print). The spread is plus 7 basis points. Across the 43 snapshots this is the widest print in the file; the previous maximum was plus 5.
Reverse repo take-up is $0.225bn (FRED RRPONTSYD, as of 4 November), so the facility is holding almost nothing. Reserve balances are $2,893.8bn (FRED WRESBAL, as of 28 October - 8 days behind the market snapshot in this piece). The Treasury's cash balance is $938.2bn (Treasury Fiscal Data, as of 3 November), from $930.8bn on 2 November.
That combination is what a dealer funds against. Secured money fixing above the administered rate means the marginal holder of inventory pays more to carry it than the facility pays to park it, and the willingness to warehouse risk falls before any spread visibly widens. Plus 7 basis points is a tilt, not a dislocation. It is also the widest tilt in the sample, and it is pointing the same way as a spread complex in the top quartile.
The labour data in the same snapshot is calm. Initial claims were 194k (FRED ICSA, week ended 24 October), from 194k - unchanged - and continuing claims 1,701k (FRED CCSA, week ended 17 October), from 1,701k. Core CPI is 2.57% year on year (FRED CPILFESL, September). Nothing in the fundamentals requires the spread widening, which is exactly why it is worth marking.
The composite fell 0.165 and stayed 0.024 above the threshold
The headline is +0.374, from +0.539. The regime is TIGHTENING, which starts at +0.35. The margin is 0.024, less than half the 0.059 mean absolute single-session move in the headline across this file. One more session like this and the label changes to NEUTRAL regardless of what credit does.
Four of the five sub-indices fell. Rates & Policy is +0.721, from +0.834; Credit & Stress +0.350 from +0.721; Growth & Inflation -0.033 from +0.127; Scarcity +0.850 from +0.945. Liquidity is -0.020 from +0.070. Scarcity remains dominant for a fourth session.
The week tells a different story from the session, and the gap is the piece. On 29 October Credit & Stress was +0.088 - the weakest of the five. It is +0.350 now, a rise of +0.262. Decomposed the same way, the two spread legs account for +0.286 of that rise and the two volatility legs -0.025. Over a week the gauge rose because credit widened. Over a session it fell because insurance got cheaper.
Both statements are true of the same index 6 sessions apart, which is the argument for never reading it without the legs. Over the week the spread legs produced +0.286 and the volatility legs -0.025; on the session the volatility legs produced 0.326 and the spread legs 0.045. An index whose dominant leg flips between one session and the next is not measuring a single quantity. It measures a blend, and the blend changes.
What would confirm it, and what would break it
The read here is that Wednesday's collapse in the stress index is a volatility event, not a credit event. The confirming case is the VIX holding below 18 and the MOVE below 95 through the next 3 sessions while high-yield OAS prints at or below 3.40% and investment grade at or below 0.93%. Insurance was expensive, it got cheap, and spreads simply stopped widening. That is a benign resolution and it is testable this week.
The credit read is invalidated by high-yield OAS tightening through 3.14% - the 28 October print - with investment grade below 0.90%. That would mean the week's 26 basis points of widening were a positioning squeeze that fully reversed, and the gauge was right for the wrong reason.
The stress read is invalidated from the other side by investment-grade OAS printing 0.95% or above while high yield holds above 3.40%. That is the migration case, and it puts the repricing in the better credits first, which is the later and worse stage. It came within 1 basis point twice in 5 sessions, so the market is close to answering.
The funding read is invalidated by SOFR-IORB back below plus 5 basis points with reverse repo take-up still under $1bn. That would make plus 7 a quarter-end artefact rather than a trend. Nothing in this snapshot supports calling it an artefact yet: the print is the widest in the file and the facility is empty.
Notes
1. Treasury levels are the 4 November close: 3M 4.21%, 2yr 4.58%, 5yr 4.69%, 7yr 4.77%, 10yr 4.90%, 20yr 5.30%, 30yr 5.28%. Session changes +0.0, -3.0, -5.0, -6.0, -5.0, -5.0, -4.0 basis points. Week-on-week from 29 October: 2yr -9.0, 10yr -15.1, 30yr -7.9. Source: exchange closes; par curve for 4 November agrees to the rounded print.
2. 2s10s 31.4 basis points, from 34.2, or -2.8 on the session; -6.1 on the week from 37.5. On the rounded par prints for 4 November the slope is 32.0. Sample: the 43 daily snapshots from 2026-09-10 to 2026-11-05.
3. 10yr real yield 2.634% on a nominal of 4.894% and inflation compensation of 2.26% (FRED T10YIE, as of 4 November). Week earlier: 2.665% on 5.045% and 2.38%. Real leg -3.1 basis points, inflation compensation -12.0. 1yr breakeven mean 2.317%, low 2.18% on 24 June, high 2.50% on 04 May.
4. High-yield OAS 3.40% (FRED BAMLH0A0HYM2, as of 3 November), from 3.43% (2 November); -3.0 on the session and +26.0 from 3.14% on 28 October. 86th percentile of the 785 observations in the file. 1yr mean 2.891%, low 2.60% on 28 August, high 3.46% on 30 March; 262 observations.
5. Investment-grade OAS 0.93% (FRED BAMLC0A0CM, as of 3 November), from 0.94%; -1.0 on the session and +7.0 from 0.86% on 28 October. 75th percentile of the 784 observations in the file. 1yr mean 0.802%, low 0.73% on 22 January, high 0.94% on 16 March. Printed 0.94% on 30 October and 2 November.
6. Excess spread, high yield less investment grade: 247.0 basis points from 228.0, +19.0 on the week. Ratio 3.66 from 3.65. All-in cost: 8.19% (28 October pair) against 8.29% (4 November 10yr, 3 November spread), +10.9 basis points; investment grade 5.91% against 5.82%, -8.1.
7. Composite headline +0.374 from +0.539; regime TIGHTENING (threshold +0.35), dominant Scarcity, 5/5 sub-indices. On 29 October the headline was +0.423. Credit & Stress input z-scores, today against the prior session: HY OAS 0.954/1.042, IG OAS 0.488/0.580, VIX -0.161/0.803, MOVE 0.119/0.460. Attribution divides each leg's change by four.
8. S&P 500 7,688.62 (+119.70, 96th percentile); Nasdaq 100 28,437.17 (+256.91); VIX 16.61 (-4.22, 12th percentile, z -0.161); MOVE 93.88 (-6.09, 45th percentile, z +0.119). All 4 November closes. Largest prior one-day VIX fall in the sample -2.27 points on 18 September; largest prior one-day S&P gain +1.49% on 22 September; prior MOVE falls -8.58 on 28 September and -8.40 on 7 October.
9. SOFR 3.97% (NY Fed, as of 3 November) and IORB 3.90% (FRED IORB, as of 4 November and unchanged on 5 November); spread plus 7 basis points, the widest of the 43 snapshots (previous maximum plus 5). Reverse repo take-up $0.225bn (FRED RRPONTSYD, as of 4 November), from $0.427bn (3 November). Reserve balances $2,893.8bn (FRED WRESBAL, as of 28 October). Treasury general account $938.2bn (Treasury Fiscal Data, closing balance 3 November).
10. Initial claims 194k (FRED ICSA, week ended 24 October); continuing claims 1,701k (FRED CCSA, week ended 17 October); CPI 3.72% and core CPI 2.57% year on year (FRED CPIAUCSL and CPILFESL, September).
11. Treasury par curve, 4 November close: 2yr 4.58%, 5yr 4.69%, 10yr 4.90%, 30yr 5.28%; 2s10s 32.0 basis points on the rounded par prints and 31.4 on the unrounded series used above. Source: US Treasury daily par yield curve, 4 November row.
12. Both charts are generated by script from this piece's own series. The waterfall uses the four Credit & Stress input z-scores on 4 and 5 November, each divided by four; the all-in chart uses the 28 October and 4 November 10yr closes against the 28 October and 3 November spread prints. Single reported values (the 3.40% OAS, the 0.93% OAS, the 2.26% breakeven) are prints for one date, not index levels; percentile ranks are positions inside this file's own history and are not comparable across series.
| TENOR | LEVEL | 1D Δ | Z (3Y) | RANGE %ILE |
|---|---|---|---|---|
| 2Y | 4.560 | +0.050 | +1.11 | 71 |
| 5Y | 4.670 | +0.030 | +1.68 | 75 |
| 10Y | 4.880 | +0.020 | +1.86 | 74 |
| 30Y | 5.260 | 0.000 | +1.61 | 76 |