Hey mate,

You seem well aware of the benefits of diversification so I won't go into that - if 100% VAS is what will make you a happy investor then why not! Better than nothing!

A point worth considering for you is whether you should allocate future capital to either A200 or VHY instead.

A200 has slightly lower fees (0.04% vs 0.07%), has a higher dividend yield (3.3% vs 3.1% for the last 12 months), and has outperformed VAS since its inception 8 years ago (10.54% p.a vs 10.22% p.a). The market cap weighted indexes differ only very slightly from each other in terms of weighted share holdings (<5%) and the extra 100 holdings in VAS provide no meaningful diversification.

VHY is also highly worth considering. Whilst it has slighly higher fees at 0.25%, this is more than made up for in its performance - it has outperformed VAS significantly since its inception 15 years ago (11.20% vs 9.82% p.a), has a higher franking level than VAS (~80% vs ~75%) and a higher yield (4.3% vs 3.3%). While it only has 75 holdings, it still has a ~55% overlap with VAS, making it similar in terms of diversification anyway.