An insider is someone who is privy to the secret information of a company and the secret information could be used to trade.

局内人掌握着公司内幕信息,这些内幕信息可以助你在交易中获利

耶鲁公开课 - 金融市场课程节选

We tend to use the term to refer to information we have about categories and intuitions we have about the typicality, our frequency of certain features of categories.

我们会用这个词来代表,我们对某些类别掌握的信息,用它来指代我们掌握典型性的直觉，指代某个类别反复出现的特性。

耶鲁公开课 - 心理学导论课程节选

If you know the secrets of a company, if you know some good news about the company before the public does, you could buy the shares of the company and experience the profit when the price goes up.

如果你掌握了公司内幕信息,你能比公众更早得知,公司的利好消息,那你就会去购买公司的股票,然后从股票升值中获利

耶鲁公开课 - 金融市场课程节选