Expel, founded in 2016 and headquartered in Herndon, Virginia, United States, has raised a total of $289 million, including a $30 million Series E round in October 2022. The company, a leader in managed detection and response (MDR), provides AI-powered cybersecurity solutions including threat hunting, phishing protection, and vulnerability prioritization. With a valuation of $1 billion as of November 2021, Expel helps businesses enhance their security operations and proactively address emerging threats with real-time detection and automation.