@alimais "Efficient Market Hypothesis" states that asset prices reflect all available information. This forum of regular vault dwellers knows exactly the same (or less, of course) than "the market". All hopes and dreams about future returns of S&P are already included in its price. Last year's Vanguard projections say that World will do better than S&P500, but this projections are already included in prices as well.
The only choice you actually have is risk level and fees, the rest is just guessing, and, again, most probable outcomes are already included in price.
@sashieng I don't have time to track single stocks over the next 18 years and I want to minimize the risk of their investment, I like the Bogle head and DCA strategy. Keep buying the Haystack and hopefully an average of 9/10% over the next 18 years will do me nicely
@alimais You've mentioned a few terms there that suggest you've been consuming financial advice for Americans; Bogle head, DCA etc. ETFs exist on both sides of the pond, but we have other forms of index funds as well, e.g. FTSE Global All Cap is a popular OEIC which you won't find on platforms which only offer ETFs instead of the wider family of index funds.
@alimais Why not both? Split your contributions 50/50. All World for sure is a better diversification option but S&P500 has historically strong returns.