If I were building a portfolio designed to last decades, I would keep it simple.
For true buy-and-hold investing, I want broad diversification, structural growth exposure, and low costs. Two Vanguard exchange-traded funds (ETFs) that tick those boxes for me right now are Vanguard FTSE Asia Ex-Japan Shares Index ETF (ASX: VAE) and Vanguard Diversified High Growth Index ETF (ASX: VDHG).
They play very different roles, but together they capture both global growth and disciplined diversification.

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Vanguard FTSE Asia Ex-Japan Shares Index ETF
This ETF provides exposure to around 1,800 stocks across fast-growing Asian economies, excluding Japan. Its country allocation is heavily weighted toward China (32%), Taiwan (22.1%), India (18.6%), Korea (14.5%), and Hong Kong (4.8%).
In other words, it gives investors direct exposure to the engines of global economic expansion.
Its top holdings include Taiwan Semiconductor Manufacturing Company, Tencent, Samsung Electronics, Alibaba, and SK hynix. These are not speculative micro-caps. They are dominant regional champions operating in semiconductors, technology, banking, insurance, and consumer sectors.
I like this Vanguard ETF because it captures demographic growth, rising middle classes, and increasing digital adoption across Asia. It also diversifies away from the US-heavy nature of many global portfolios.
It won't outperform every year. Emerging markets can be volatile. But over a multi-decade horizon, I believe exposure to Asia is essential. That is why I see the VAE ETF as a buy-and-hold forever ETF.
Vanguard Diversified High Growth Index ETF
This ETF invests across multiple Vanguard index funds, targeting approximately 90% growth assets and 10% defensive assets. Its strategic asset allocation includes Australian shares, international shares (both hedged and unhedged), emerging markets, international small caps, and fixed income.
For investors who want simplicity, I think this structure could be incredibly powerful.
Instead of picking regions or rebalancing manually, the Vanguard Diversified High Growth Index ETF handles the diversification internally. It spreads capital across Australian shares (around 36%), international shares (over 40% combined when including hedged exposure), emerging markets, small companies, and bonds.
That built-in diversification reduces reliance on any single country, sector, or theme. It also smooths out some volatility compared to a pure equity portfolio, while still maintaining a strong growth tilt.
I see this Vanguard ETF as an ideal set and forget ETF. If someone told me they wanted one fund to hold for 20 or 30 years and didn't want to tinker with allocations, this would be near the top of my list.
Foolish takeaway
For me, buy-and-hold investing is about owning broad exposure to long-term growth without constantly trying to outsmart the market.
The VAE ETF gives direct access to Asia's expanding economies. The VDHG ETF offers a diversified, growth-focused portfolio in a single trade.
Different roles, different risk profiles, but both are ETFs I would feel very comfortable holding forever.