What is meant by “global” in this context?
Does it mean any purchased by U.S. citizens?
The only thing this could practically mean is that they want to impose a transaction tax on all of the U.S. exchanges, nomatter the location of the person making the transaction or the location of the broker or the company whose stock is being bought or sold.
What it would be is a terrific gift to the Nikkei exchange and all of the other various exchanges around the world that didn't impose this stupid fee on transactions. It would make plain sense for lots of companies to de-list from American exchanges and list on foreign exchanges. I'd be perfectly happy to buy some shares of CAT or GE on the London exchange instead of the NYSE.