Tax rates are negative, zero, or nominal for most people. There are perhaps 100 million people who pay a substantial amount of income taxes in the US (I am fudging around various numbers to make the math easier, here; see http://www.taxfoundation.org/research/show/1410.html for information on how many people simply don't pay taxes). So that's an average of $7000 per serious taxpayer. $7000 is 5% of $140,000. Do you think a typical 40 year-old taxpayer has a $140,000 equity portfolio?