The European Commission formally endorsed the financial transaction tax agreed to by eleven of the 27 members. The tax will be set at 0.1% for stocks and bonds and 0.01% for derivatives. The tax will go into effect at the start of 2014, by which time the participating countries will give it formal approval.
There seems to be two purposes of the tax. The first is to raise revenue. The EC projects the tax will raise 30-35 bln euros annually where ever and whenever an instrument from eleven is traded. This would seem to block the ability to avoid the tax by moving transactions out of the eleven countries. It reinforces the "residence principle". This essentially means that if some one is a resident of the eleven countries, or acting on behalf of a resident, the transaction will be taxed anywhere it takes place. The other purpose is to deter the high frequency trading, which some officials see as largely unnecessary and potentially destabilizing.