Target-Date Funds
A target-date fund holds a complete portfolio in one holding and shifts it gradually from equities toward bonds as a chosen retirement year approaches. It removes every ongoing decision, which is its value, and it hides two decisions worth examining: the fee and the shape of the glide path.
A target-date fund is a portfolio sold as a single holding, with a schedule built into it. The schedule is the product, and it is the part almost nobody examines before buying.
How it works
You pick a year — usually close to when you expect to retire — and buy the fund with that year in its name. Inside it is a portfolio of equity and bond funds, often global.
The mix shifts automatically over time, holding more equities when the date is distant and moving toward bonds as it approaches. Nothing is required from you at any point.
It also rebalances internally, which quietly solves the maintenance task most people skip entirely.
The date is a label
Two funds with the same year in the name can hold materially different equity weights, because the provider chooses the glide path and there is no standard.
The most important distinction is “to” versus “through”. A to fund reaches its most conservative allocation at the target date and stops. A through fund keeps reducing equities for years or decades afterwards, on the assumption you will still be invested.
Those are different products with the same label, and the difference is largest exactly when it matters — in the years around retirement.
A worked example
Take a fund charging 90 basis points against an equivalent charging 12.
On this site’s arithmetic, 75 basis points a year removes 20.2% of a thirty-year pot and 150 removes 36.5%.
A 78-basis-point gap sits squarely in that range, so the expensive version costs roughly a fifth of the result over a career — for a portfolio that is broadly the same.
Which makes the fee the entire comparison between two target-date funds, since the underlying allocations differ far less than the prices do.
What it buys
Measured on the S&P 500 since 1950, 93% of trading days ended below the previous record and the longest wait for a new record was 7.5 years, from 1973 to 1980, and the index still went on to new records. Most of the time something is falling.
A single-holding fund gives you nothing to rearrange during that. That is the behavioral product, and for many people it is worth more than the fee difference between the cheapest options.
It also removes the decision that gets postponed most — rebalancing — by making it automatic and invisible.
Where it fits badly
In a taxable account, its automatic rebalancing generates disposals you did not choose the timing of. A target-date fund is built for a sheltered account and behaves less well outside one.
It also cannot coordinate with anything else you hold. If it is one of several holdings, the overall allocation is the sum of its schedule and your other decisions, which is usually not what either was designed for.
Which means it works best as the whole portfolio or not at all.
Costs
Moving between funds costs the spread, and every trade pays the bid-ask spread. Inside a wrapper that is the whole cost; outside one, the disposal matters more.
The funds are typically among the largest in a plan’s menu, so liquidity is never the constraint.
How to compare two of them
Read the fact sheet for three numbers rather than the name. The current equity weight, the weight at the target date, and the fee.
Those three describe the product completely, and two funds sharing a year in their names can differ by twenty points of equity at the date — which is a larger difference than most people would accept if it were presented as a choice.
The original data
Among the 24,971 unique videos in the search study behind this site, the nearest subjects are workplace plans, in 22 videos at a median of 81,626 views, and index funds, in 132 at 69,951.
It is the default investment of most workplace retirement plans, so it is worth knowing how the glide path and the fee actually work before accepting it.
The question: Retirement is 30 years away. Pick a later date for more equities?
The answer is that choosing a later date is a legitimate way to hold a higher equity weight, and it should be a decision rather than a trick. The date is a dial for allocation, not a promise about when you retire. Picking 2065 instead of 2055 to get more equities is fine if you would hold that allocation deliberately — and is a way of quietly overriding your own risk tolerance if you would not.
When it fails
The common failure is holding one alongside other funds, which defeats its entire design. The target-date fund manages its own allocation on a schedule and has no knowledge of the individual equity fund sitting next to it, so the actual portfolio is neither the glide path nor anything anybody chose. It drifts in a direction determined by whichever component performs, and the automatic rebalancing corrects only its own internal weights — making the overall allocation harder to understand than if nothing had been automated at all.
The second failure is not checking the fee. The portfolios are similar; the prices are not.
A third is assuming the date means the same thing everywhere. To and through differ.
A fourth is holding one in a taxable account. Its internal trading is not tax-aware.
A fifth is picking the date from your birth year rather than your allocation. It is a dial.
And a sixth is switching out after a bad year. The whole value was in not having to decide.
Related
The glide path is the schedule inside the fund. Asset allocation is what it is doing on your behalf. And expense ratio is the one number that separates two of them.
The honest comparison is not against a portfolio you could build — it is against the portfolio you would actually maintain. A target-date fund at a slightly higher fee that rebalances itself for thirty years beats a cheaper three-fund portfolio that drifts for a decade because nobody got around to it.
— Michael Whitman
This page is educational, not financial advice. Test every idea on your own charts before risking money.