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 a detailed prospectus—basically a comprehensive business plan and financial report that tells potential investors everything they need to know about the company before buying in. You'll encounter S-1s when a company announces its IPO (initial public offering). They matter because they're packed with honest information about the company's finances, risks, and leadership—stuff the company is legally required to disclose. For example, if TechStartup Inc. filed an S-1, you'd learn about their revenue, losses, and whether the CEO has ever faced fraud charges.