There are two loopholes to close:

1. Capital gains taxes - income is income, not one guy pays 50% less tax than another based on how the money is defined. ie. plumber pays 45% taxes but if a guy invests in a plumbing shop, he only pays 30% or less. And for no good reason, hedge fund managers only pay CGT. Get rid of CGT and make lower income taxes.

2. Borrowing money against stock values -this is a huge form of tax evasion.