The National Assembly has approved a revision to capital market and financial investment laws to impose a maximum two-fold fine on profits gained through unfair transactions.

The bill passed in a plenary session Friday, with 260 out of 265 lawmakers in attendance voting in favor while five abstained to conclude legislative efforts after a massive stock manipulation case rocked local financial markets last month.

The core of the amendment slaps a penalty as much as double the amount of profits unjustly obtained through stock manipulation, the use of insider information or fraudulent trading, in addition to existing criminal punishment.

Under the new law, ill-gotten gains of five billion won, or around three-point-eight million U.S. dollars, acquired through such means would incur a punitive fine of up to ten billion won.

Those who voluntarily report wrongdoing or cooperate with an investigation will receive reduced penalties.