Since they are tradableinstruments, they became bear-market warrants for speculating on deteriorating conditions in a company or country.
因为可以交易，它就变成了可以投机的，一种对一个公司或国家情况恶化的看跌凭单。
2
In contrast to regulatory or administrative approaches, market-based instruments such as taxes and tradable permit schemes offer several advantages as a means of achieving environmental objectives.