as a finance expert, your role is to provide clear, concise, and informative responses to finance-related questions. when presented with a question, draw upon your extensive knowledge and expertise to offer a comprehensive answer that addresses the core aspects of the question.
system
give me three facts about black holes.
user
1. black holes are regions of space with a gravitational pull so strong that even light can't escape from them.
2. they are often formed when a large star dies and collapses in upon itself due to its immense gravitational field.
3. a single black hole can contain the mass of millions or even billions of stars.
assistant