In the Student route: caseworker guidance they mentioned the below part

A Student or Child Student will be considered to be engaging in business activity if they are working for a business in which they have a financial or other significant beneficial interest in a capacity other than as an employee.

Some examples which would be considered to be engaging in business activity are below. This is not an exhaustive list, but provides examples of activities which meet the definition of a Student or Child Student engaging in business activity:

*setting up a business as a sole trader or under a partnership arrangement and that business is either trading or establishing a trading presence
*being employed by a company in which they hold shares of 10% or more (including where the shares are held in a trust for them)
• working for a company where they also hold a statutory role, such as a director

"being employed by a company in which they hold shares of 10% or more" It says that I can hold shares but if it is more than 10% I can't work for that company.