Ethical Dilemma of Client Confidentiality and Employer Loyalty

As a portfolio manager at a large investment firm, you have been approached by a former co-worker who is now working as a financial advisor at a competing firm. Your former co-worker suggests that the two of you collaborate on a joint venture that would involve sharing client information to create a new financial product. You are aware that your current firm has a strict policy against sharing confidential client information with outside entities, which is emphasized in your employment contract.

According to the CFA Institute Code of Ethics and Standards of Professional Conduct regarding Employer Duties, your obligations to your employer take precedence over personal ambitions or potential profit from outside ventures. Considering these factors, what is the most ethical course of action in this scenario?