BPP FM 裡面關於T-bill的問題 - 金融分析師

Question 6.17

A T-bill maturing in 150 days for $1,000,000 has a current price of $979,167.

A T-bill maturing in 60 days for $1,000,000 has a current price of $993,333.

Calculate the future price of a 90-day T-bill to be delivered in 60 days.

解答的答案是

(1+rf)^(T-t)=1,000,000/993,333

F(t,T)=St(1+rf)^(T-t)=979,167*1,000,000/993,333=985,739

我想請問的是為什麼St可以用979,167去代


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