Form 4

Form 4 is a document that insiders at a company—like executives, board members, or major shareholders—must file with the SEC (the government agency that oversees stock markets) whenever they buy or sell shares of their own company's stock. You'll see these filings on the SEC's website, and they matter because insider trading activity can signal whether company leaders think the stock is undervalued or overpriced. If the CEO of TechCorp suddenly buys 10,000 shares, that might suggest she believes the stock will rise. Form 4s are public records, so retail investors can use them as one clue—though not a guarantee—about where insiders think their company is headed.