Securities and Exchange Act Article 159

A securities broker shall not accept any discretionary authorization that allows them to determine the type, quantity, or price of securities to be bought or sold on behalf of the principal.
中文原文 證券交易法第159條
證券經紀商不得接受對有價證券買賣代為決定種類、數量、價格或買入、賣出之全權委託。

English translation for reference only; the Chinese text prevails. Not legal advice.