Thank you for the opportunity to help you with your question!
Regulatory bodies have proven helpful to finanacial markets because they allow participants to have confidence necesary toexecute transactions and invest knowing that they will be protected against abusive behavior and undue risks
The market stop when a certain stock prices fall bellow a threshold could be improved to account for company circunstances and be a dynamic instead of fixed cutoff percent
Please let me know if you need any clarification. I'm always happy to answer your questions.