Best solution I've come across is a small <1% fee on all financial transactions. Which would work well if all those transactions in the world occurred on a blockchain.
Many countries have tried it, and it usually ends like this [1] implementation by the Swedes from 1984-1991. Then they cancelled it after witnessing the devastation to their economic sector.
"During the first week of the tax, the volume of bond trading fell by 85%, even though the tax rate on five-year bonds was only 0.003%. The volume of futures trading fell by 98% and the options trading market disappeared. 60% of the trading volume of the eleven most actively traded Swedish share classes moved to the UK after the announcement in 1986 that the tax rate would double. 30% of all Swedish equity trading moved offshore. By 1990, more than 50% of all Swedish trading had moved to London. Foreign investors reacted to the tax by moving their trading offshore while domestic investors reacted by reducing the number of their equity trades.
As a result, revenues from these taxes were disappointing. For example, revenues from the tax on fixed-income securities were initially expected to amount to 1,500 million Swedish kronor per year. They did not amount to more than 80 million Swedish kronor in any year and the average was closer to 50 million. In addition, as taxable trading volumes fell, so did revenues from capital gains taxes, entirely offsetting revenues from the equity transactions tax that had grown to 4,000 million Swedish kronor by 1988."
The TL;DR is that a transaction tax would primarily serve to increase bid-offer spread, which slows down the markets and results in every industry selling slightly less at slightly higher prices - which naturally means slightly shifting to favour those with more purchasing power.
This guy is giving the method a shot: http://www.basicincome.co/