Large size is less of a problem if a fund invests in very large, liquid companies
But you should still monitor this as there could be problems
Don't put too much of your money into one of these or any other types of funds
The size of a fund is important if it invests in areas such as smaller companies because if it is too large it cannot invest in all the available options. Taking a reasonable stake relative to the fund's size could mean owning a large proportion of one company, which could make it harder to dispose of a holding in it or buy more in the proportion it wants. And if a fund’s holding in a UK-listed company exceeds 30 per cent of its voting shares, it would have to make a takeover offer.
Fund size is less of an issue for global equities funds such as Fundsmith Equity that invest in very large global companies, as even if they put a meaningful percentage of their assets into one of these, they would still only hold a fraction of such a company’s overall market cap. But even with these types of funds you cannot ignore size.