I am now engaging in a yield curve estimation project.
I met very strange market data and I would like to ask how I should understand this paradox to practitioners and/or researchers in R.G. who have experiences with the derivative valuation. If there are other proper forums to post this theme, please teach me those forums’ names.
The problem is an inconsistency between 6month Libor, 12-month Libor and 1year swap rate.
I got the following rate as on 2/23/2017 from Bromberg.
USD 6-month Libor USD: 1.36239%
USD 12-month Libor: 1.74428%
USD 1-year swap rate: 1.2965%
Apparently, 6 month Libor and 12-month Libor higher than 1-year swap rate mean an arbitrage opportunity and it can be verified as follows.
We can get the discount rates with 6-month maturity and 12-month maturity from 6-month Libor and 12-month Libor as follows.
6 month discount rate=1/(1+0.5*1.36239/100)=0.993234139
12 month discount rate=1/(1+1.74428/100)=0.982856235
Applying these to 1-year swap cash flow leads to its present value as
0.5*1.2965/100*0.993234139+(1+0.5*1.2965/100)*0.982856235=0.995666241.
The present value should be 1 to satisfy the no-arbitrage condition.
The difference between 1 and 0.995666241 is not negligible since implied 12-month Libor consistent with the swap present value 1 is 1.299427122% which is very lower than the actual rate.
The explanation such as a swap contract is a bilateral contract cancelling out counterparties' credit risks each other partially and the Libor deposit is one-sided transaction seems inappropriate to me.
Suppose a bank A enters into 1-year swap agreement as a fix-payer with a bank B and at the same time bank A borrow a 6-month loan and make it 12-month deposit with another bank C.
6 month later, bank A will pass through 6-month Libor from bank B to bank C and roll over the loan with 6 moths Libor.
12 month later, bank A will pass through 6-month Libor again and redemptions of the initial 12-month deposit and 6 months later bellowing cancel out.
Receipt 12-month Libor from bank C and payment the lower fix rate to bank B shows an arbitrage opportunity.
Best regards