Guide

High-yield bonds (junk bonds) explained

Harbor Capital lifted its high-yield bond allocation from 6% to 11% of fixed income in March when option-adjusted spreads widened past 500 basis points over Treasuries — a level that historically preceded above-average forward returns if defaults stayed below 4%. By August, two energy issuers in the passive ETF sleeve had entered distressed exchange offers, and the headline yield masked a −3.8% price drawdown as credit spreads gapped wider on a single weak payroll print. Operations refactored the sleeve: split passive beta from a fallen-angel tilt, capped CCC exposure at 8%, and tied position adds to trailing twelve-month default rates rather than spread level alone.

High-yield bonds — often called junk bonds — are corporate debt rated below investment grade (typically BB+ and lower by S&P and Fitch, or Ba1 and lower by Moody's). Issuers pay higher coupons because lenders demand compensation for default risk, covenant weakness, and thinner liquidity than investment-grade corporates. High yield is a distinct asset class: equity-like drawdowns in recessions, income-like coupons in expansions, and a spread cycle that rewards investors who buy widening and trim tightening. This guide covers rating tiers, spread and default math, fallen angels and rising stars, fund vehicles, the Harbor Capital credit sleeve refactor, a technique decision table versus investment-grade bonds and BDCs, pitfalls, and a production checklist.

Rating tiers: where “junk” begins

Credit ratings are opinions, not guarantees — but they define index membership and fund mandates. The high-yield universe spans:

Tier	Typical ratings	Risk profile
Upper high yield	BB+ / Ba1 to BB− / Ba3	One notch from investment grade; often larger issuers; lower default frequency
Core high yield	B+ / B1 to B− / B3	Mid-cap and leveraged issuers; bulk of index weight; cyclical default sensitivity
Distressed / CCC and below	CCC+ / Caa1 and lower	Elevated default risk; option-like payoffs; small index slice but large loss contribution in stress

Investment-grade starts at BBB− / Baa3. The boundary matters because many pension and insurance mandates cannot hold sub-IG paper — forced selling when issuers are downgraded (“fallen angels”) can create temporary mispricings. Conversely, upgrades (“rising stars”) often compress spreads as IG buyers enter.

Yield, spread, and what you are actually paid for

A high-yield bond's stated coupon is not your expected return. Decompose yield into components:

Risk-free rate — Treasury yield for matching maturity; the baseline.
Credit spread — extra yield over Treasuries for default and liquidity risk; see our credit spreads guide for cycle signals.
Illiquidity premium — smaller issues and distressed names trade wider bid-ask spreads; ETFs absorb some of this, single bonds do not.
Convexity and call risk — many HY bonds are callable; yields fall when spreads tighten as issuers refinance away from expensive coupons.

Yield to worst (YTW) is the standard comparison metric — the lowest yield among yield-to-maturity, yield-to-call, and put options. Screen on spread duration (sensitivity to spread moves) as well as interest-rate duration; in risk-off episodes, spread widening often dominates rate moves for HY portfolios.

Default and recovery: the math behind junk

High-yield investing is a probability game. Historical U.S. annual default rates average roughly 3–4% through full cycles, spiking above 10% in severe recessions (2009, 2020). Loss given default depends on seniority:

Senior secured — higher recovery (often 50–70 cents on the dollar); common in leveraged loans, less in classic HY bonds.
Senior unsecured — typical HY bond structure; recoveries often 30–50% in bankruptcy.
Subordinated / PIK-heavy — lower recoveries; payment-in-kind coupons accrue debt rather than cash.

Expected loss approximates default rate times (1 minus recovery rate). A 5% default rate with 40% recovery implies 3% annual principal loss before coupons — which is why headline yields must exceed that breakeven. In tightening cycles, falling defaults lift total returns; in widening cycles, mark-to-market losses arrive before defaults peak — spreads are forward-looking.

Fallen angels, rising stars, and covenant trends

Fallen angels are bonds downgraded from investment grade to high yield. Index rebalancing forces IG-only funds to sell, sometimes depressing prices below fundamental value — dedicated fallen-angel strategies buy the dislocation. Rising stars are upgrades from HY to IG; spread compression benefits holders but reduces forward yield.

Structural shift since 2010: covenant-lite loans and bonds strip traditional lender protections (debt incurrence tests, restricted payments). Issuers gain flexibility; lenders accept higher loss severity in downturns. When screening individual issuers, read indentures for change-of-control puts, asset-sale covenants, and subordination — not just the rating badge.

How to hold high yield: ETFs, funds, and single bonds

Vehicle choice shapes liquidity, diversification, and tax efficiency:

Broad HY ETFs — instant diversification, daily liquidity, transparent holdings; track indices with rules-based inclusion; fee drag ~0.40–0.50%.
Fallen-angel ETFs — tilt to downgraded IG names; different risk than broad HY; often larger average issue size.
Active mutual funds / SMAs — manager discretion to avoid deteriorating issuers; potential alpha and risk of underperformance; watch turnover and fees.
Individual bonds — precise maturity and issuer selection; requires $1,000+ minimums and dealer markup; illiquid in stress — suitable for investors who can hold to maturity and diversify across 20+ names.
Closed-end funds (CEF) — can use leverage to boost yield; persistent NAV discounts or premia add a second pricing layer; see closed-end funds explained.

Most retail investors are better served by diversified funds than concentrated single-issue bets unless they have credit research capacity.

Cycle timing and portfolio role

High yield correlates with equities in crashes — it is not a Treasury substitute. Typical roles in a portfolio:

Income sleeve enhancer — 5–15% of fixed income when spreads are wide and default outlook is benign.
Equity substitute (cautious) — lower volatility than stocks in calm markets but still risk assets; do not double-count equity and HY beta.
Tactical spread trade — add on widening, trim on historic tights; requires discipline and macro view.

Pair HY with duration hedges or duration-aware IG allocations when rates are uncertain. In recessions, prioritize quality within HY (BB over CCC) rather than maximizing yield.

Harbor Capital credit sleeve refactor

After the August drawdown, Harbor Capital rebuilt HY exposure around risk budgeting instead of spread chasing:

Split beta and alpha — 70% broad HY ETF for market exposure; 30% active fallen-angel sleeve for downgrade dislocations.
Quality floor — no CCC weight above 8% at purchase; rebalance if index drift pushes higher.
Default trigger — pause new adds if trailing twelve-month par-weighted default rate exceeds 4.5% unless spreads are above the 75th percentile of twenty-year history.
Sector caps — energy and retail capped at 12% each; lessons from prior cycle concentration losses.
Correlation check — when HY correlation to S&P 500 exceeds 0.75 over sixty days, trim 2% to short-duration Treasuries.

The sleeve now reports spread contribution, default contribution, and rate contribution separately in monthly attribution — so yield changes are not mistaken for skill.

Technique decision table

Vehicle	Best when	Weak when
Broad high-yield ETF	Diversified beta, daily liquidity, transparent costs	You need to avoid specific sectors or CCC tails
Fallen-angel strategy	IG downgrade waves create forced selling; you want larger issuers	HY fundamentals are deteriorating broadly, not just ratings migration
Investment-grade corporate ETF	Lower default risk, smoother drawdowns, rate-sensitive income	You need higher coupons and can accept credit volatility
BDC or private credit	Direct lending economics, floating coupons, middle-market exposure	You want exchange liquidity and public mark-to-market pricing
Bank-loan / leveraged-loan fund	Senior secured, floating rate, covenant packages (when not lite)	Callable loans reset lower when rates fall; retail fund liquidity gates in stress
Single HY bonds	You have credit research edge and hold-to-maturity capacity	You need liquidity or hold fewer than fifteen issuers

Common pitfalls

Chasing yield — highest-yielding quintile often carries disproportionate defaults.
Ignoring spread cycle — buying at historic tights leaves little cushion for widening.
Treating HY as safe income — drawdowns of 15–30% occur in credit crises.
CCC concentration — small index weight can drive large portfolio losses.
Callable surprise — refinancing removes high coupons when you wanted yield.
Fund liquidity mismatch — daily NAV funds holding illiquid bonds can gate redemptions in stress.
Double equity risk — heavy HY plus heavy stocks amplifies risk-off pain.
Tax inefficiency — ordinary income coupons in high brackets without shelter.

Production checklist

Define sleeve role: income enhancer vs tactical credit bet; set max allocation.
Screen on YTW and OAS vs ten-year median; document entry spread level.
Check index or fund quality mix: BB%, B%, CCC% weights.
Review trailing twelve-month default and recovery rates vs long-run averages.
Map sector concentration; cap cyclical exposure (energy, retail, autos).
Compare ETF expense ratio or active fee to historical excess return.
Stress-test: −10% price shock on HY sleeve within total portfolio.
Verify liquidity: fund AUM, bid-ask, days-to-liquidate single bonds.
Model after-tax yield in taxable vs tax-deferred accounts.
Rebalance on spread regime change or when correlation to equities spikes.

Key takeaways

High-yield bonds pay extra coupon for real default risk — headline yield is not expected return.
Spread widening hurts prices before defaults peak; cycle timing matters as much as issuer selection.
Fallen angels and rising stars create migration trades distinct from broad HY beta.
Diversified ETFs suit most investors; single bonds demand research depth and position count.
Size HY as a risk asset within fixed income — pair with quality and duration awareness.