HOW TO SOLVE e^2R= 0.90506?

Shazam023

New Member
'm doing Swaps valuation and discounting coupon pmts. with spot rates.
so there's an example in Hull which asks for final pmt's spot rate.

so m not able to solve this e^2R=0.90506 for R...
can someone help?

R shud be 4.99%

and is there any other way to calculate R other thn e^x.
earlier i was using 1/(1+r)^n but through that m getting 5.11%:confused:
 

Shazam023

New Member
Hi @Shazam023, e^2R=0.90506, you can solve it using LN , like 2R=LN(0.90506). as 2R=-0.09975. R=-0.09975/2=-0.04988=4.99%. Please ignore the signs. Hope that helps. Thank you:)!

@Deepak Chitnis thnkx man.... this is so simple..

can u explain that is there any difference in these 2 terms:

e^(0.02)(3/12) & 1/(1+0.02)^3/12

i m using the second term for discounting purposes but in books the "e^x" term is used and my answers r just lil bit different.. 2~3 decimal point difference....
 

Dr. Jayanthi Sankaran

Well-Known Member
Hi @Shazam023,

e^(-0.02)*(3/12) = 0.995012 and 1/(1 + 0.02)^3/12 = 0.995062. The former uses continuous compounding and the latter uses discrete compounding (annual, semi-annual compounding etc.). Hull always uses continuous compounding in his interest rate calculations. However, Tuckman and some others use semi-annual discrete compounding. In Japan they use discrete annual compounding.

That is why in the Chapter on Swaps (which can be thought of as a long position in a floating rate bond with a short position in a fixed rate bond and vice-versa), Hull uses continuous compounding.

However, it must be clarified here that while Hull computes the coupon cash flows using semi-annual discrete compounding, he uses continuous compounding to discount those cash flows. Hope that helps!

Thanks!
 
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