Asset Allocation5 分钟阅读

The Core-Satellite Strategy

'Parking everything in an index feels boring, but betting it all on stocks I like feels scary.' Have you ever wrestled with these two feelings? The core-satellite strategy is a way to design exactly that middle ground.

What are the core and the satellite?

As the name suggests, it is a way of splitting assets into a 'core' and 'satellites.' Picture small satellites orbiting the sun (the core) and it becomes easy.

The core is the stable backbone that makes up most of the portfolio. It usually contains broadly diversified, low-cost assets like index funds or ETFs that track a market index such as the S&P 500 or KOSPI 200, or bonds. The goal is to move steadily 'at the market average.'

The satellite is the remaining small portion of assets. It's the place to hold specific sectors you're interested in (e.g., semiconductors, healthcare), individual stocks, or specific regions to aim for returns better than the market average (the so-called 'alpha'). In exchange, its volatility is greater too.

It helps to understand the core as the 'don't-get-it-wrong' part and the satellite as the 'try-to-do-better' part. The satellite doesn't always deliver excess returns—it can also produce losses.

How is the ratio usually set?

There is no fixed right answer, but combining various sources, it is generally set in the range of core 70–90% and satellite 10–30%. A commonly cited example is 80:20.

You adjust it to your risk profile. If you value stability, you enlarge the core to 9:1 or 8:2; if you want to be more aggressive by accepting volatility, you might increase the satellite to something like 6:4. Just remember that the more you enlarge the satellite, the greater the whole portfolio's swings (volatility) and maximum drawdown become as well.

The weight of any single satellite holding is usually kept small, around 5–10% of the total. This is to keep the whole from being shaken even if one part collapses badly.

The ratios written here are not a specific right answer but the 'approximate ranges' commonly mentioned across various overseas and domestic sources. This article does not recommend any specific ratio or product.

Why split this way? — A story about fees

One big reason core-satellite is often discussed is exactly 'cost management.'

Index ETFs that hold the whole broad market tend to have very low management fees (total expenses), sometimes as low as 0.03–0.2% per year depending on the product. In contrast, active funds or frequent individual trading often carry more in fees, transaction costs, and taxes.

If you fill most of your assets (the core) with low-cost indexes, then even if you layer a relatively expensive product or active trading onto the small remainder (the satellite), the 'overall weighted-average cost' does not rise much. It's like confining the expensive cost inside a small sleeve. Conversely, if you buy and sell the satellite frequently, transaction costs and taxes pile up accordingly, so keep that in view too.

Fees may look small 'right now,' but over a long period they eat into returns through compounding. Core-satellite is an idea to structurally reduce this cost leakage.

Strengths and limits

The strengths are clear. With the core, you don't miss the market average, and with the satellite you get the 'fun and learning' of participating in areas you care about. Because most of it sits in a diversified core, you are less shaken psychologically too.

There are limits as well. The excess return the satellite aims for may not actually materialize, and the result could even be worse than just holding the core. A satellite concentrated in a specific sector or stock can have a larger drawdown when the market swings, and can go through a long drawdown duration before recovering.

That's why the key is to limit the size of the satellite to 'an amount that, even if lost, won't collapse the whole plan.' And as time passes and the ratio drifts, you come to consider rebalancing back to the target ratio.

The drawdowns and drawdown durations introduced here really happen. Checking the maximum drawdown and recovery period of crisis periods with your own eyes on our site helps when deciding your satellite weight.

常见问题

Q. Must the core contain only index ETFs?

It's not a rule, but because the core's purpose is a 'broadly diversified, stable backbone,' it heavily uses low-cost, diversified assets like index funds/ETFs that track a market index, or bonds. The key is 'whether it avoids concentration in one or two stocks, and whether the cost is low.'

Q. What if the satellite fails to produce excess returns?

That's entirely possible. The satellite is only a place to 'aim for' alpha (returns above the market average); it isn't guaranteed. That's why you keep each satellite holding small (e.g., 5–10%) and cap the satellite's total share, designing it so that losses don't shake the whole plan.

Q. Is it good to buy and sell the satellite frequently?

Frequent trading increases transaction costs and taxes. One of this strategy's appeals is 'cost management,' and if trading in the satellite becomes too frequent, that advantage shrinks. This article does not recommend any trading frequency; it only points out that it's important to also look at how costs affect returns.