S-1 filing (IPO prospectus)

An S-1 filing is the official document a private company submits to the SEC (Securities and Exchange Commission) when it wants to go public and sell shares to regular investors for the first time. Think of it as the company's detailed job application to the stock market—it includes their business plan, financial history, risks, and how they'll use the money raised. You'll encounter S-1s when a company announces an IPO (initial public offering), and they matter because they're your best source of unfiltered information before deciding whether to buy in. For example, when TechStartup Inc. files an S-1, you can read exactly how much debt they have and whether their main product is actually profitable, not just what their marketing says.