Target-date funds
One fund that changes its stock-and-bond mix over time. What the glide path does, what it costs and when it is enough.
Target Date Funds — Autopilot Investing
A target date fund makes one decision for you and then keeps making it for thirty-five years. That is the entire product. You pick the year, set a monthly contribution, and the fund slowly moves your money from stocks into bonds while you get on with your life. It is the closest thing in investing to a default setting, and for a lot of people the default is the right answer.
The arithmetic that matters is not the fund's. A 30-year-old contributing $350 a month at 7% a year retires at 65 with about $630,369. At $200 a month the same 35 years produce about $360,211. The glide path everyone talks about is worth far less than the contribution rate, which is why a slightly boring fund you never touch beats a clever one you keep adjusting.
What happens to one contribution
Inside a target date fund sit four or five index funds: US stocks, international stocks, bonds, sometimes a short-term bond sleeve. You never see them, but they do all the work.
- 01Your contribution arrivesOnce a month, from your paycheck or 401(k)
- 02It is split across index fundsUS stocks, international stocks, bonds
- 03The mix is rebalancedBack to the target whenever markets push it off
- 04The target shifts each yearA little less stock, a little more bond, until retirement
You make one decision, the year. The fund makes every later one on a schedule, including the ones people get wrong in a panic.
What the glide path actually does
The slow shift from stocks to bonds follows a curve the industry calls a glide path. A 2060 fund, bought today by someone planning to retire around 2060, roughly follows this shape:
- Stocks
- Bonds
Between 25 and 35 almost nothing happens. The real shift to bonds is packed into the last fifteen years, exactly when most people pay the least attention.
Illustrative glide path. Real funds differ: some reach 50% stocks at retirement, some keep 60% for another decade.
That shape is a choice, not a law. Two funds with the same target year can sit twenty percentage points apart on stocks at age 55. Read your fund's glide path once. If the stock share at your retirement age is not the risk you want, pick a different year, or a different fund.
The fee is the part you control
Every target date fund is a fund of funds, and you pay the underlying funds' costs plus the wrapper. The gap between the cheapest and most expensive options in a typical 401(k) is large, and it compounds for exactly as long as you hold the fund.
- 0.08% a year
- 0.12% a year
- 0.55% a year
- 0.73% a year
The four bars hold the same investments. Only the yearly fee differs, and after thirty years the cheapest ends $12,444 ahead of the dearest, about a sixth of the final balance.
Illustrative. $10,000, no further contributions, 7% a year before costs, the fee subtracted from the return each year, no taxes.
When a target date fund is the right answer
- Typical cost
- 0.08% to 0.20% for the cheap ones
- Better: 0.03% to 0.10%
- Rebalancing
- Better: Automatic
- Once a year, by you
- Control over the mix
- None
- Better: Complete
- In a taxable account
- Poor: internal rebalancing can pass you gains
- Better: Fine: you choose when to sell
- Chance you panic and tinker
- Better: Low
- Higher
VerdictIn a 401(k) or IRA, with a fund under 0.20%, the target date fund is a complete answer. The three-fund portfolio wins only if you want the control and will actually use it calmly.
Buy it when the alternative is worse. If you are 28 on a normal salary and your other option is a portfolio you will build "once things calm down", the target date fund wins by default. With $4,000 invested, a three-fund portfolio is more spreadsheet than money. If your 401(k) offers one cheap target date fund and nothing else index-shaped, take it and stop reading.
Buy it too if you know a 40% drawdown would make you sell. A fund that rebalances without asking you is a behavioral device as much as a financial one, and 0.08% for a mechanism that stops you panicking is cheap.
Skip it if you want control over the mix. Someone who wants 100% stocks at 45 because a pension covers the basics does not need a fund quietly moving them into bonds. And skip it in a taxable brokerage account: when the fund rebalances internally, it can pass capital gains to you whether or not you sold anything. Retirement accounts are where these funds belong.
Four ways people break a good fund
Holding three of them. Overlapping target dates do not diversify anything. They average out to one fund with extra paperwork.
Holding it next to a stock fund you liked. Now your real allocation is the fund's mix plus whatever you added, and nobody is managing the total. A small-cap fund next to a 2060 fund is how a 90/10 portfolio quietly becomes 95/5.
Stopping contributions at the bottom. Two years of missed $300 payments from age 33, $7,200 in all, would have grown to about $62,500 by 65 at 7%. Downturns feel like the moment to stop. Arithmetically they are the moment to continue.
Retiring into it without a withdrawal plan. The glide path ends at retirement; the spending does not. A fund at its final 45/55 mix still has to be drawn down in some order, and that plan is yours to write.
Look up the expense ratio first
Under 0.20% is good; over 0.50% is a reason to compare the funds underneath.
Pick the year closest to your retirement
Aim at the year you turn 65 unless you have a reason not to.
Set the contribution, not the balance
A standing order of $300 a month beats a $10,000 lump sum you keep postponing.
Read the glide path once
Find the stock share at your retirement age. If it is not the risk you want, pick another year or fund.
Then leave it alone
Check the fee every few years. Nothing else needs your attention.
A target date fund will not beat the market, and it will not lose to a well-built three-fund portfolio by much either. What it does is remove dozens of chances a year to make an emotional decision with your retirement money. For most people, that is worth more than the fee difference.
56 more deep dives are in the Navigator library.
