That is completely up to you. However, when making this decision, there are a few things to take into consideration. If an employee has 5% ownership or more it is seen as a substantial interest. If this is the case, the employee will be taxed in box 2 for the increase in value. On our platform you can make sure an employee can not get more ownership than 4.9%. Besides that there is a feature that allows you to approve or disapprove of every trade.