1) Because Warren Buffett Says So!

"The goal of the non-professional should not be to pick winners – neither he nor his “helpers” can do that – but should rather be to own a cross-section of businesses that in aggregate are bound to do well. A low-cost S&P 500 index fund will achieve this goal."

2) Because Indexs are Low Cost and Unit Trusts are High Cost

"My advice to the trustee could not be more simple: Put 10% of the cash in short-term government bonds and 90% in a very low-cost S&P 500 index fund. (I suggest Vanguard’s.) I believe the trust’s long-term results from this policy will be superior to those attained by most investors – whether pension funds, institutions or individuals – who employ high-fee managers."

If you purchase the STI ETF you are only paying 0.30 of a percent each year as ......