What Bonds Actually Are (and What They Are Not)
Bonds are loans. When you buy a bond, you are lending money to a government (a gilt, in UK terminology) or a company (a corporate bond) in exchange for regular interest payments and the return of the principal at a fixed future date. Unlike equities, which represent ownership of a company and carry the full upside and downside of its fortunes, bonds are debt instruments — the issuer owes you a defined amount, and you have a legal claim on it.
This distinction matters for FIRE planning. Bonds do not grow in the way equities do. Over long periods, global equities have returned roughly 7–10% per year in nominal terms; bonds have returned perhaps 2–5%. But bonds are also considerably less volatile. A global equity index can fall 40–50% in a crash; a government bond portfolio typically falls far less and often rises as investors seek safe-haven assets during equity market turmoil.
For the FIRE investor, bonds are not about growing wealth — they are about protecting it at specific, strategically important moments.
During Accumulation: Why Young Investors Generally Do Not Need Bonds
For someone in their 20s or 30s with a FIRE timeline of 15–25 years, holding bonds makes limited rational sense. The argument for bonds — they are less volatile and protect against short-term losses — is relatively unimportant when you have decades before you need the money. Short-term portfolio volatility is not a risk for someone with a long time horizon. It is an inconvenience, and often an opportunity to buy equities at lower prices.
The real cost of holding bonds in the accumulation phase is the opportunity cost of lower expected returns. Consider a £500 per month investor over 30 years. At 6% real annual returns (all equity): approximately £502,000. At 4.5% (a blended equity-bond portfolio): approximately £380,000. That difference of £122,000 — a reduction of 24% in the final portfolio — is the cost of de-risking too early. For most accumulation-phase FIRE investors, this is an expensive form of unnecessary protection.
The exception is an investor whose psychological relationship with market volatility makes holding a 100% equity portfolio difficult to sustain. An investor who panic-sold in March 2020 and bought back in after recovering prices would have been better served by a smaller equity allocation they could hold through the volatility. The best portfolio is the one you stick with. If bonds are the price of staying invested, they may be worth it — but the right response for most investors is to understand the nature of market volatility rather than to structurally underweight equities for decades.
The 5–10 Years Before Retirement: When Bonds Become Relevant
The purpose and relevance of bonds changes fundamentally as retirement approaches. The reason is sequence of returns risk— the danger that a severe market downturn in the years immediately before or after retirement permanently impairs the portfolio’s ability to sustain withdrawals.
During accumulation, a 40% market fall is painful but recoverable — you have years of future contributions to buy at cheap prices and time for the portfolio to grow back. At the point of retirement, that same 40% fall dramatically reduces the portfolio from which you will be drawing income. If you are withdrawing £35,000 per year from a portfolio that just fell from £900,000 to £540,000, you are suddenly withdrawing at 6.5% rather than 3.9% — a rate that makes portfolio survival highly uncertain.
This is the window during which bonds earn their place. Introducing bonds five to ten years before retirement reduces portfolio volatility precisely when volatility is most dangerous. A portfolio of 70% equity and 30% bonds is meaningfully less likely to suffer a catastrophic drawdown in the critical pre-retirement window.
The Bond Tent Strategy
The bond tent — also called a rising equity glide path — is the most evidence-supported approach to managing bond allocation around the retirement transition. The mechanism is:
- Start increasing bond allocation approximately 5–7 years before retirement.Shift gradually from, say, 100% equity to 70% equity and 30% bonds over this period.
- Reach peak bond allocation on or near the retirement date.The “tent peak” — the highest bond allocation — provides maximum protection against sequence of returns risk at the most dangerous moment.
- Reduce bond allocation gradually over the first 5–10 years of retirement.As time passes, sequence of returns risk diminishes — the portfolio has demonstrated it can sustain withdrawals and has had time to recover from any early downturn. The tent descends back toward a higher equity weighting, capturing long-run growth over the remaining decades of retirement.
Research has shown that this rising equity glide path in early retirement outperforms both a fixed allocation and a declining equity path (the traditional “reduce equities as you age” approach) in terms of portfolio survival rates. The rationale is counterintuitive but solid: you want more equities during the stable middle of retirement, not just during accumulation.
In Retirement: The Cash Buffer and Short Bonds
Once in retirement, the most practical defensive position is a combination of a cash buffer and short-duration bonds, with the majority of the portfolio remaining in equities.
A cash buffer of one to two years of spending provides immediate income without requiring any equity sales. During a market downturn, you draw from cash rather than selling equities at depressed prices. When markets recover, the cash buffer is replenished by selling equities at recovered prices. This simple mechanism significantly improves portfolio survival in poor market sequences.
Short-duration government bond funds (UK gilts with a maturity of under five years, for example) provide a secondary buffer layer that is less volatile than equities but more liquid and predictable than long-duration bonds. They act as a bridge between the cash buffer and the equity core, replenishing cash as needed while providing modest returns above pure cash.
UK Gilts vs Corporate Bonds vs Global Bond Funds
For UK FIRE investors, the most commonly used bond vehicles are:
- UK gilts (government bonds). Issued by the UK government, gilts are the safest UK debt instruments. They are held in the ISA or pension tax-free, and short-duration gilt funds (such as the Vanguard UK Short-Term Gilt Index fund) are a clean defensive holding with very low costs.
- Global government bond funds.Provide geographic diversification beyond UK gilts. The iShares Core Global Aggregate Bond ETF or similar instruments hold bonds from multiple sovereign issuers. They introduce some currency risk unless hedged; currency-hedged global bond ETFs (denoted with “GBP hedged” in their name) address this.
- Corporate bonds. Offer higher yields than government bonds but with higher credit risk. During equity market crashes, corporate bonds often fall alongside equities (as credit risk rises), somewhat undermining their defensive purpose. For most FIRE investors, government bonds rather than corporate bonds serve the defensive role more cleanly.
- Index-linked gilts. UK government bonds whose principal and coupon rise with inflation. These offer explicit inflation protection but have performed poorly in the high-interest-rate environment of 2022–2024 due to their long duration. They are a specialist holding suited to specific inflation-hedging purposes rather than a core defensive allocation.
How Much Bond Allocation Is Enough?
A practical guide for different FIRE stages:
- 20+ years from retirement: 0–10% bonds (possibly zero for most investors)
- 10 years from retirement: begin transitioning, targeting 20% bonds by year 5
- 5 years from and 5 years into retirement: 25–35% bonds at the tent peak
- 5–15 years into retirement: gradually reduce back toward 80–90% equity
- Later retirement (20+ years in): equity-heavy again, supplemented by cash buffer for income smoothing
These figures are not rules. Risk tolerance, portfolio size, spending flexibility, and the presence of the State Pension as an income floor all modify the appropriate allocation. Someone with a very low spending rate relative to portfolio size faces less sequence of returns risk and may need fewer bonds at every stage. Someone with minimal flexibility in spending and no other income sources may want more. The principle — start with equities, introduce bonds as retirement approaches, descend back toward equities in early retirement — is more important than the specific percentages.