If you still hold doubts about your trading activity then it is best to ask for the opinion of immigration consultant for saving status of visa.
With these guidelines, international students can definitely approach issues of stock ownership in the UK. On different sides, frequent trading activity may still be considered to be breaking the terms of your visa. You also want to seek professional advice from an immigration consultant for clarification on the gray area between permissible investment and impermissible business activity.
Remember, your principal motive in the UK is to study. Participation in the stock market ought to be cautious and long-term in nature; it is not meant to serve as a principal source of income.