[Accused of committing the biggest mistake in the history of the US Treasury Department! Yellen quickly "cried out" for himself. Recently, former Soros deputy and billionaire investor Stan Ruckenmiller publicly accused US Treasury Secretary Yellen of failing to sell more long-term bonds using previously low interest rates close to zero, committing the "biggest mistake in history". Yellen countered this accusation on Thursday. Yellen was asked to respond to this accusation in a media interview on Thursday evening. She stated that the US Treasury has been extending the average maturity of its bond investment portfolio, and "in fact, the current maturity of the investment portfolio is almost the longest in decades.