Insider trading means the trading of public companies' stocks and other assets on stock markets using secret information. This is done by getting people who have confidential or non-public facts about how much a stock is really worth to tell traders so they can buy or sell to make profit and manipulate that particular
stock. A stock could be worth more or less than the public knows, depending on how well a company is doing in making money, new innovations, sales and demand.
In many countries, insider trading with secret information is against the law.