Theranos was a biotech startup founded in 2003 by Elizabeth Holmes, promising revolutionary blood-testing technology that required significantly less blood than traditional methods. It attracted over $700 million in funding, reaching a valuation of $10 billion at its peak. The startup claimed its technology could diagnose a range of diseases with just a few drops of blood. However, investigations led by journalists, notably John Carreyrou of The Wall Street Journal, revealed that the technology was fraudulent, leading to legal battles and the company shutting down in 2018.