Form 4

Form 4 is a document that insiders—like executives, board members, or major shareholders—must file with the SEC (Securities and Exchange Commission, the government agency that oversees stock markets) whenever they buy or sell shares of their own company. You'll see these filings on the SEC's website and financial research sites, usually within a couple of days of the transaction. They matter because insider trading activity can signal whether company leaders believe the stock is undervalued or overpriced, giving retail investors a peek into what the people closest to the business are actually doing with their money. For example, if a CEO suddenly sells a large chunk of shares, that might be worth paying attention to.