It wouldn't "destroy" the market, saying that is hyperbole and lowers the credibility of opposition to this bill. End-users are enough to have *some* market activity - for example the real estate market only has end-users, there are no intraday dealers in real estate. However, what it would do is slash liquidity and volumes. You can sell a stock in a few seconds, at close to the last advertised price. To sell a house takes weeks to months, and you often have a 10% bid-offer spread. Imagine the benefits if you could sell your house quickly at a 0.1% spread, or buy a house just as easily.
Killing off intraday trading, which this tax will do, will have that kind of effect - higher costs, wider spreads, less liquidity etc. There is a reason it was repealed in the 1960s in the USA, and why even socialist Sweden repealed it after a failed experiment in the 1980s. In the UK it is avoided by a market-maker exemption loophole, which just allows registered firms to get the profits rather than a more competitive level playing field open to all - not exactly good for the retail or institutional end-user, and rather nepotistic, helping out City elites, the opposite of the intent of the bill.
Killing off intraday trading, which this tax will do, will have that kind of effect - higher costs, wider spreads, less liquidity etc. There is a reason it was repealed in the 1960s in the USA, and why even socialist Sweden repealed it after a failed experiment in the 1980s. In the UK it is avoided by a market-maker exemption loophole, which just allows registered firms to get the profits rather than a more competitive level playing field open to all - not exactly good for the retail or institutional end-user, and rather nepotistic, helping out City elites, the opposite of the intent of the bill.