Quote from Anaconda:
And no, it won't kill the capital markets, not even close. Lose the illussion that the daytrader is soooo important to today's markets, it's simply not true. The effect will be less significant than you think.
One rather significant effect, depending on who's excluded, will be that spreads will go up. A lot. Given that the "big boys" are excluded or have ways around it, it will mean the difference in billions a year going to big Wall Street firms vs. the "end users" of the markets -- investors and productive companies needing capital.
On the other hand, if it's airtight and there are no exemptions for anyone (which would probably take a globally coordinated effort), then it will inject a large amount of friction into global capital markets. In this case, I don't think anyone really knows what the long-term effects will be, although my GUESS is that it will generally be negative for the global economy.