Fiduciary duty of portfolio managers requires separate client accounts, minimum investment thresholds, prohibition on borrowing and client-directed management. Regulation 15 requires portfolio managers to distinguish discretionary from non discretionary management, maintain a minimum investment threshold for new and fresh client investments, and act in a fiduciary capacity. Managers must hold client funds in a separate account at a Scheduled Commercial Bank, transact within Reserve Bank limits, refrain from deriving benefits or borrowing on clients' behalf, and not lend client securities except as permitted; they must also handle client complaints promptly.