I disagree with the conclusion, but the explanation is good:
The term systemically important financial institution is all over the news these days. It refers to financial institutions that are so big, or interconnected, or unique that they pose a risk of taking down the entire financial system should they fail. A researcher at the Federal Reserve Bank of Cleveland is proposing a three-tiered system for regulating systemically important financial institutions. This video helps explain the proposal for those who aren’t policy wonks.