[參考] Treasury Yield 30 Years

參考資料：

• US Department of the Treasury - Resource Center - Historical Treasury Rate. 選擇 30 YEAR NOMINAL，這是我的 k1無風險利率。
• Yahoo! Finance - Treasury Yield 30 Years (^TYX).
  

再請參考：Testimony by Chairman Bernanke on the economic outlook and the federal budget situation
February 2, 2012. 預期 Treasury Yield 30 Years 會上漲，但企業會越來越難賺錢。