8-K (Material Event)

An 8-K is a form that publicly traded companies must file with the SEC (the government agency that oversees stock markets) whenever something important happens that could affect the stock price. Think of it as a company's way of saying "Hey, something big just went down." You'll encounter 8-Ks when researching stocks because they're often the first official announcement of major news—like a CEO resignation, a lawsuit, a big acquisition, or a major product recall. The SEC requires these filings so investors like you get timely, honest information instead of hearing rumors. For example, if TechCorp announced it was being acquired by MegaCorp, they'd file an 8-K the same day so all investors learn about it simultaneously.