One way of interpreting ethics in the financial services sphere, in my opinion, is that ethics is an awareness of the differences between an unfair and a fair competitive market outcome. At the moment regulation enforces the rights of one (the transaction) while ignoring the rights of the other (the right to advice that equates with the representation). This is both unfair and arguably unethical.
If an efficient competitive market outcome depends on knowledgeable rationale parties, each with the same knowledge and expertise and ability, then price, supply and quality of service/product can be unequivocally determined.
But if both sides to an agreement are not so equally endowed, and indeed, if the true nature of the relationship is misrepresented, then we risk an unfair and imperfect outcome.
Business ethics, in my opinion, is an awareness of the difference between a fair outcome that would result in a truly competitive market and an unfair outcome that would not and acting in honour of the contract to counter the deficit.
Since it would be commercial suicide for a company that is interested only in the returns on transactions to come out and state the dynamics of the relationship, a different reality is often represented. I feel that it is the representation and communicated intent that must be honoured and that must represent, in terms of fairness, the differential between the represented outcome and the actual outcome.
One way of ensuring that asymmetry in knowledge, expertise and ability do not impact a competitive market outcome where an important representation of conduct and care has been made is to accord a best interests standard.
Current regulation of the transaction when the service that is often being represented is one of advice is clearly unfair and unequivocally unethical, but it also leads to imperfect market outcomes.