Rakuten Securities
楽天証券Brokerage (NISA/iDeCo) · Rakuten Securities
- Fees
- Varies
- English
- Partial
A leading low-cost brokerage for NISA and index-fund investing, integrated with Rakuten points and Rakuten Bank.
All-country vs S&P 500 funds
What each includes, concentration, currency exposure, cost, overlap, and which investor each may fit.
Direct answers
An all-country fund spreads across many countries including the US and Japan, while an S&P 500 fund concentrates in large US companies; the choice is between global diversification and a deliberate US bet — and holding both mostly duplicates US exposure.
Key points
- All-country ≈ the whole listed world by market weight (the US is already its largest part).
- S&P 500 = large US companies only; higher concentration in one country.
- Because the US is ~60%+ of a global index, holding both mostly overlaps.
- All-country adds currency and country diversification; S&P 500 is a one-country valuation bet.
- Do not choose based on recent performance — that reflects one regime, not the future.
What each includes
An all-country fund holds companies across developed markets, emerging markets, and Japan, weighted by market size. Because US companies are the largest share of global market value, the US is already the biggest single component of an all-country fund — often well over half. An S&P 500 fund holds only large US companies.
So the practical difference is the non-US portion: an all-country fund adds Japan, Europe, other developed markets, and emerging markets that the S&P 500 leaves out. If you hold both, you are mostly buying the same US large caps twice, with a smaller genuine addition of non-US exposure from the all-country fund.
Which fits you
Choose an all-country fund if you want a single, hands-off, globally diversified equity holding and prefer not to bet on one country. Choose an S&P 500 fund if you deliberately want US concentration and accept the single-country risk. There is no universally correct answer, and recent US outperformance is not a reliable reason — it reflects one historical regime.
The overlap warning matters most: buying both an all-country and an S&P 500 fund does not double your diversification; it just overweights the US relative to the rest of the world. If you want more US than global weights imply, that is a valid choice — just make it deliberately, not by accidentally stacking overlapping funds.
Who this is for
- Beginners deciding their single core fund
- People who own both and wonder about overlap
What this is not
- Readers seeking a performance prediction
- US taxpayers before review
Important cautions
- Holding both overweights the US and does not add much diversification; decide the US weight deliberately.
Related products & services
SBI Securities
SBI証券Brokerage (NISA/iDeCo) · SBI Securities
- Fees
- Varies
- English
- Partial
Japan’s largest online brokerage by accounts, with a very broad low-cost fund lineup and full NISA/iDeCo support.
Monex Securities
マネックス証券Brokerage (NISA/iDeCo) · Monex
- Fees
- Varies
- English
- Partial
An established online brokerage often chosen for US-stock access and research tools, with NISA and iDeCo support.
Frequently asked questions
What should a beginner invest in inside NISA?
This is education, not a recommendation. Most beginners research low-cost, broadly diversified index funds — for example all-country (全世界株式) or S&P 500 trackers — rather than picking individual stocks, because low fees and diversification are within your control while returns are not. Understand that values fall as well as rise, match the risk to your time horizon, and never invest money you may need soon.