High Yield (HYG) vs Short Treasury (SHY)

HYG (iShares iBoxx $ High Yield Corporate Bond ETF) holds U.S. high-yield corporate bonds rated below investment grade (BB and below). April 2026: 30-day SEC yield approximately 7.5 percent, modified duration approximately 3.5 years, AUM approximately $15 billion, expense ratio 0.49 percent. The portfolio holds approximately 1,200 bonds across 950-plus issuers.

SHY (iShares 1-3 Year Treasury Bond ETF) holds nominal Treasury bonds maturing in 1 to 3 years. April 2026: 30-day SEC yield approximately 3.81 percent, duration 1.9 years, AUM approximately $25 billion. The HYG/SHY pair compares high-yield credit risk against the cleanest cash-equivalent benchmark, with the yield differential of approximately 370 basis points providing a direct read on the high-yield credit spread component.

HYG/SHY is significantly cleaner than HYG/TLT for isolating credit risk. HYG duration 3.5 years vs SHY 1.9 years (1.6-year duration mismatch). A 100 basis point yield rise produces 3.5 percent HYG decline and 1.9 percent SHY decline (1.6 percent NAV difference per 100bp). This is small relative to typical credit spread moves of 200 to 1,500 basis points (which produce 7 to 50 percent HYG price moves).

By contrast, HYG/TLT (TLT duration 17 years) has 13.5-year duration mismatch, producing 13.5 percent NAV difference per 100bp parallel shift. The duration noise dominates the credit signal in HYG/TLT but not in HYG/SHY. HYG/SHY is therefore the cleanest credit-risk gauge in liquid ETFs, suitable for direct credit-spread views without taking the absolute-rate risk that pure duration trades carry.

The HY OAS (Bloomberg High Yield US OAS, ICE BofA H0A0) measures option-adjusted spread of U.S. high-yield bonds over the Treasury curve. April 2026: HY OAS 280 basis points, near 25-year tights. Long-run average: 550 basis points. The lowest reading sub-300bp was last seen 2007 pre-GFC, suggesting late-cycle territory.

The HYG-SHY yield differential approximately tracks HY OAS plus duration premium. HYG SEC yield 7.5 percent minus SHY 3.81 percent equals 369 basis points. The differential exceeds reported HY OAS (280bp) by approximately 90 basis points, reflecting the longer effective duration of HYG (3.5 years vs implied zero of OAS calculation). HYG/SHY ratio at 1.05 is near multi-year highs, consistent with HY OAS at multi-year tights.

2008 to 2009 GFC produced the largest credit cycle drawdown in modern history. HY OAS rose from 360 basis points (December 2007) to 1971 basis points (December 2008), a 1611 basis point widening over 12 months. HYG declined approximately 30 percent peak-to-trough; SHY rose approximately 6 percent.

HYG/SHY ratio fell from 1.10 to 0.62 (43 percent ratio compression). After Fed PMCCF (Primary Market Corporate Credit Facility) and aggressive monetary response, the ratio recovered to 0.95 by December 2009 and 1.05 by 2011 as HY OAS retraced to 500 basis points. The 2008 to 2009 episode established HYG/SHY as the cleanest single-pair representation of the credit cycle in liquid ETFs.

March 2020 produced the fastest credit shock in modern history. HY OAS rose from 320bp (February 2020) to 1083bp (March 23, 2020), a 763 basis point widening over 30 days. HYG declined 21 percent peak-to-trough; SHY rose 2 percent. HYG/SHY ratio fell from 1.10 to 0.85 (23 percent compression).

The Fed announced PMCCF and SMCCF (Secondary Market Corporate Credit Facility) on March 23, 2020, including direct purchase of corporate ETFs and individual bonds. The intervention triggered immediate recovery: by April 30, 2020, HY OAS retraced from 1083bp to 700bp; by December 2020, HYG/SHY ratio rebuilt from 0.85 to 1.05 as HY OAS retraced to 386bp. The episode established Fed credit-market backstop as a permanent feature of the post-2020 regime.

HY OAS reached 280bp in April 2026, near 25-year tights. The tight-spread era reflects: (1) record corporate balance sheet quality post-2020 deleveraging, (2) Fed easing 100 basis points September to December 2024 reducing default risk, (3) low default rates (3.5 percent vs 4 percent long-run average), (4) record cash on corporate balance sheets, (5) muted issuance constraining supply.

HYG/SHY ratio at 1.05 reflects this tight regime. The ratio has been compressed from 0.95 (October 2023 trough during Fed hike cycle peak) to 1.05 currently. The compression reflects credit spread tightening despite stable absolute yields, a textbook risk-on regime configuration. The Iran war produced minor effects (HY OAS widened from 250bp to 280bp briefly, then settled), confirming credit markets pricing minimal recession risk despite the supply shock.

April 2026 trailing 12-month default rate: approximately 3.5 percent (per ratings agency and bank research estimates). Long-run average: 4.0 percent (1981 to 2024). Peak: 14 percent (1991), 13.5 percent (2008 to 2009), 8 percent (2020 COVID). Default rates lag HY OAS by 6 to 12 months.

April 2026 spreads at 280bp are pricing default rates of approximately 1.5 to 2.5 percent over the next 12 months, well below the current 3.5 percent. The pricing implies the credit cycle is at or near peak quality. Historical episodes: 2007 sub-300bp HY OAS preceded GFC by 9 months; 1999 sub-300bp HY OAS preceded the dot-com cycle by 12 months. The 2026 pattern fits the late-cycle template.

HYG portfolio composition: BB-rated approximately 50 percent, B-rated 35 percent, CCC and below 15 percent. The CCC composition is the most rate-sensitive segment, and CCC OAS typically widens 3 to 5 times faster than BB OAS during credit stress.

April 2026: BB OAS 200bp, B OAS 350bp, CCC OAS 750bp. The CCC-BB spread of 550bp is near 5-year tights (long-run avg 800bp). Compression in CCC-BB historically signals late-cycle dynamics where speculation drives lowest-quality buying. The 2007 pre-GFC and 2019 pre-COVID periods both saw CCC-BB compress to similar levels before sharp re-widenings. The pattern suggests outsized exposure to CCC during late-cycle creates significant downside risk in subsequent stress.

Setup 1 (35 percent probability): Continued tight spreads, soft landing. HY OAS holds 250 to 300bp. HYG returns 7 to 9 percent over 12 months (carry plus modest spread tightening). SHY returns 3.5 to 4 percent. HYG outperforms 4 to 5 percentage points.

Setup 2 (30 percent): Recession plus spread widening. HY OAS widens to 700 to 1000bp. HYG declines 15 to 25 percent. SHY rises 4 to 6 percent. HYG underperforms 20 to 30 percentage points. Trade: short HYG, long SHY. Setup 3 (20 percent): CRE-driven credit stress. The 2027 CRE maturity wall ($2.2 trillion of loans, 40 percent refi at +200 to +400bp) drives HY OAS to 500 to 700bp. HYG declines 5 to 10 percent. SHY positive 4 percent. HYG underperforms 9 to 14 percentage points. Setup 4 (15 percent): Stagflation, Fed hikes, OAS widens to 600bp+. HYG declines 10 to 15 percent. SHY declines 1 to 2 percent. HYG underperforms 10 to 15 percentage points.

Basic dashboard: track HYG/SHY ratio alongside HY OAS. April 2026 levels: ratio 1.05, HY OAS 280bp.

Three rules. First, ratio above 1.10 typically signals HY OAS below 250bp (very late-cycle territory, historically preceded major drawdowns within 9 to 12 months). Ratio below 0.95 typically signals HY OAS above 500bp (mid-cycle stress). Ratio below 0.80 typically signals OAS above 1000bp (acute crisis). Second, ratio compression of more than 0.05 over 30 days typically signals credit stress emerging, often leading equity by 5 to 15 days. Third, ratio expansion above 1.10 sustained typically marks late-cycle peak; subsequent re-widening within 6 to 12 months is the historical pattern. The 2026 setup with ratio at 1.05 sits at the upper end of the post-2010 range, consistent with late-cycle pricing.