今天10/5/2023, 周四, 是 T Bill 中 4 week 和 8 week 的 auction day，也是13 week，26 week， 和 52 week的 issue day。
下面把6期（4、8、13、17、26、52 week）的 T Bill 汇总如下，包括它们的最新 auction出来的利率，以及计算后的等效利率，以作对比。
为了更为清晰，做出当今的 T Bill 周数和等效利率的关系曲线, 并和一年前的数据相对比：
T Bill 利率计算如下：
Treasury Calculation Examples 033104 v11.xls (treasurydirect.gov)
只是读起来很头疼。最后抄来一段CD 利率的计算方法：
Formula for Calculating CD Interest
A = P(1+r/n)(nt)
- A is the total that your CD will be worth at the end of the term, including the amount you put in.
- P is the principal, or the amount you deposited when you bought the CD.
- R is the rate, or annual interest rate, expressed as a decimal. If the interest rate is 1.25% APY, r is 0.0125.
- n is the number of times that interest in compounded every year. Most CDs pay interest that is compounded daily, so n = 365. Check with your bank to verify the interest is compounded daily.
- t is time, or the number of years until the maturity date.
