Target-Date Funds vs Money Market Funds
A target-date fund holds a mix of shares and bonds that automatically shifts toward safer assets as a chosen year approaches. A money market fund holds very short-term debt and aims to keep its value stable, so it grows only by whatever short-term interest rates pay.
These do opposite jobs and get confused because both are described as safe or sensible. One is a long-horizon growth vehicle that reduces its own risk over time; the other is a place to hold cash that is not trying to grow at all.
What each one is
A target-date fund holds a mix of shares and bonds and shifts it automatically toward safer assets as the named year approaches. Target-date funds covers the glide path.
A money market fund holds very short-term debt and aims to keep its value steady, paying whatever short-term rates provide. Money market funds covers it, and ETF investing covers the wrapper both use.
One has a horizon built in and the other does not. Whereas a target-date fund is a single decision covering decades, a money market fund makes no assumption about when you need the money — which is why it is the right place for money you might need soon.
Where they differ
Whether it changes over time. The target-date fund is designed to become more conservative as the date approaches, without you doing anything. A money market fund is the same product on the day you buy it and twenty years later.
What each is exposed to. The target-date fund carries market risk that reduces over its life. A money market fund carries very little price risk and a great deal of interest-rate sensitivity in its yield — what it pays follows short rates and can fall close to nothing when they do.
What safe means in each. A money market fund is low-risk rather than free of risk — the distinction has mattered historically, and a fund holding short-term debt is still holding somebody else’s debt.
How the charge lands. Both charge annually and it compounds: over thirty years, 20 basis points removes 5.8% of a pot and 75 removes 20.2%. On a money market fund the charge is a direct subtraction from a small yield, which makes it proportionally far more damaging.
Where they agree
Both are pooled funds, bought through an ordinary brokerage or pension account, with holdings you can read.
Both charge an ongoing fee that applies to the balance every year regardless of activity.
Both are single decisions rather than strategies. Neither requires you to have a view about anything.
And both can be held inside a tax wrapper, where the wrapper rather than the fund decides the tax treatment.
Which one to use
Use a target-date fund when the money has a distant date attached. Retirement, a child’s education, anything more than a decade away — the glide path is doing real work and the alternative is rebalancing it yourself every year for thirty years.
Use a money market fund when you might need the money within a couple of years. Anything with a near date should not be exposed to a market that on this site’s shared series spent 95% of bars below a prior peak, with the longest wait for a new high at 73 bars.
Use a money market fund as a waiting room rather than a destination. It preserves purchasing power poorly over long periods, because short rates rarely beat inflation by much.
And check the target-date fund’s glide path before assuming it matches your plan. Two funds with the same year in the name can hold very different mixes at that date.
Why the date in the name is not the whole product
Because funds disagree about what happens at the date. Some are built to be held through it and keep shifting afterwards; others are built to be arrived at. Those are materially different products with the same label, and the difference decides how much market exposure you have in the years you can least afford it.
And because the years immediately before the date are the ones that matter. A fall early in a long horizon is recoverable; the same fall a year before you need the money is not, which is the entire reason the mix changes at all.
The original data
Of the 24,971 unique videos in the search corpus, neither of these subjects appears in a single title. Not one video on target-date funds, and not one on money market funds — in a corpus where scalping appears 706 times and crypto 901.
Zero coverage on both. These are two of the most widely held products in retail investing and the search corpus contains nothing about either, which is the largest supply gap measured anywhere on this site — and it is not because the audience is small, it is because neither subject makes a compelling thumbnail.
On the chart above the horizon settles it. Eighteen months is not long enough for a market to recover from an ordinary decline, which is the whole reason the two products exist separately.
When it fails
The characteristic failure is holding a money market fund for years because it feels safe. It preserves the number and not the purchasing power — short rates frequently sit below inflation, so a balance that never falls can still buy less each year, and because the statement never shows a loss the erosion is invisible. Someone who moved to cash during a decline and stayed there experiences this as prudence for as long as it takes to notice, and the loss is real even though no line on any statement ever went down.
A second failure is assuming a target-date fund matches your risk tolerance. The date is the only thing you chose; the mix behind it was chosen by the provider.
A third is treating a money market fund as carrying no risk at all. It is low-risk, which is a different claim, and the gap between the two has mattered historically.
A fourth is ignoring the ongoing charge, which removes 20.2% of a thirty-year pot at 75 basis points and is proportionally worse on a low-yielding fund.
And a fifth is holding both without deciding which money is which. The horizon is the whole basis of the choice, so a portfolio with no assigned horizons cannot be allocated correctly by definition.
Related
Target-date funds covers the glide path and what the date means. Money market funds covers short-term debt and yield. And ETF investing covers the pooled wrapper both use.
The target-date fund is the closest thing retail investing has to a finished product — one decision, then decades of rebalancing you never have to think about. It is also the least discussed, which tells you something about what gets made rather than what works.
— Michael Whitman
This page is educational, not financial advice. Test every idea on your own charts before risking money.