Re: How do I buy the Vanguard Index 500 Investor VFINX (total Stock Index)? Firstly don't buy VFINX. It's a mutual fund so any gains you make will be taxed at 41%. Instead buy VOO it's exactly the same (also run by vanguard with ultra low fees) however it's an US domiciled ETF so only 33% CGT tax applies to gains. For the Total US Stock index use VTI (Vanguard Total Index) or ITOT. To buy them, Use Degiro.ie - They charge 0 for buying these particular ETF's. This means you can dollar cost average at no additional cost.