To deter insider dealing, more cases need to be bought and a fair penalty applied. Under the civil penalty, a large fine and the proceeds of the offence can be taken. This effectively makes the person bankrupt. In addition, the person cannot work in finance again, removing the chance to reoffend and imposing another substantial penalty.
This is more than proportionate to the offence.
By using the civil route, the burden of proof is reduced to balance of probabilities rather than beyond all reasonable doubt. This should increase the speed of bringing prosecutions and allow more cases to be bought. Currently the length of time it takes in the UK is unlawful in the US! This would create a better deterrence.
With a lack of prison spaces, it seems odd to take spaces up (with the state paying) where there are no direct victims and a harsh alternative penalty can be given.
It would also take away the dual route of using the civil penalty or the criminal penalty. This is too open to political gain- as many have speculated is currently the case.