High frequency trading increases volatility in stock markets and mean that only those with access to high-powered computers can compete. This is not good for long-term thinking and means that what a company actually does is irrelevant to the stock performance – contradictory to claims about how the market ought to work. Enter the concept of a Tobin tax. In the US, the Congressional Budget Office proposed that such a tax can make a massive and positive difference for the government and society at large.
So how much would this tax on Wall Street raise? Even accounting for certain other revenues that would go down as a result, The CBO says that “This option would increase revenues by $777 billion from 2019 through 2028.”
In other words, you could raise nearly $80 billion a year over the next decade with a small tax that is well-targeted to the investor class, and which would have the salutary effect of discouraging a practice that already serves to rob the public. To give just one example for context, you could fund virtually the entire federal food stamp program with this financial transactions tax.