The Benefits of a Financial Transactions Tax
A financial transaction tax is a tax placed on a specific type of financial transaction for a specific purpose.
From the Center for Economic and Policy Research (CEPR):
The recent economic turmoil has generated renewed interest in a financial transactions tax (FTT). While such a tax will be vigorously opposed by the financial industry, it offers a very attractive mechanism for raising revenue that is arguably efficiency-enhancing. Calculations based on 2000 trading volumes showed that a set of scaled transactions taxes, imposed on transfers of stock and other financial assets, could raise more than $100 billion a year, even assuming large reductions in trading volume.
See more about Financial Speculation Taxes (a.ka. Financial Transactions Taxes) from CEPR.