Pricing Interest Rate Swaps - YouTube

Channel: Patrick Boyle

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Hello and welcome back to my channel. Today's video is my third video in a
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series on swaps. Today we'll learn about two different approaches to pricing
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interest rate swaps. Hi guys welcome back to my YouTube channel if this is the
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first one of my videos you've watched, you should check out some of the others.
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We're trying to learn about quantitative finance and derivatives.
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Make sure you subscribe if you'd like to see more content like this. Anyhow let's
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get on with it and learn about how we price interest rate swaps. We'll work
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through the example from my book, which is called "Trading and Pricing Financial
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Derivatives. There's a link to it in the description below. As explained in my
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first video on swaps, which is linked to above, swaps are usually structured such
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that they can be valued at zero at inception. This allows the two parties to
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the swap to get going without any cashflow. A swap can be priced at zero
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when the NPV or net present value of both cash flows is equal. Once the swap
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agreement has been entered into, it can take on a positive or a negative
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value, and that just occurs once the market rates for whatever the two cash
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flows are changes. Swaps are a zero-sum game,
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meaning that one counterparties gain is equal to the other counterparties loss.
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If you receive fixed in a swap, the swap value equals the present value of the fixed
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cash flows, minus the present value of floating cash flows. If you pay fixed in
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a swap, the swap value equals the present value of floating cash flows, minus the
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present value of fixed cash flows. So basically what I'm saying is that the
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value of the swap equals the present value of whatever you're receiving, less
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the present value of whatever it is that you have to pay out. Hopefully that makes
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sense to you and it's not very complicated.
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For this reason, swaps are amongst the easiest derivatives that there are to
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value. There's no complicated formula like with the Black Scholes Merton model.
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There's no stochastic calculus, no drawing of lattices like in the
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Binomial Tree and no generating price paths like with the Monte Carlo Method. All you
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have to do is lay out the expected cash flows and then present value them.
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That's really all there is to it, and then the swap is worth to you the
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present value of what you get less the present value what you have agreed to
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pay. Whatever profit you've made on the swap your counterparty has lost and
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whatever loss that you might have made on the swap your counterparty will have
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gained. That's it, once we know that, we can use whichever method we prefer to
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present value the cash flows. If you've ever priced a bond you can
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price a swap. Some people get a little bit confused when valuing a swap
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because we sometimes lay out the cash flows a little bit differently to how
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you might lay them out when you're pricing a bond, but essentially it's
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still the same thing we just kind of group it all together into a table with
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a swap because you're able to see it all at once. but in truth you can just price
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one bond, price the other bond and you know the the value of the swap. It is what
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you're receiving less what you're paying. So you can do this however you want but
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In my book I cover two approaches so let's work through them here. A plain
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vanilla interest rate swap can be priced as either a combination of a long
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position in one bond and a short position in another bond, or as a
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portfolio of forward rate agreements. All of the discounting is done using LIBOR zero
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coupon interest rates, as it's assumed that the risk on the cash flows is
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equivalent to a loan in the interbank market. Let's start out with a
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description of a swap and then we will value it using each of our different
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approaches suppose that a swap has been in existence for some time already and
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that we now are looking to value it assume that it pays floating six month
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LIBOR versus 5% fixed semi-annually it's on a hundred million dollars notional
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and has 1 and 3/4 years remaining to maturity suppose we know that LIBOR
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continuously compounded is 6% six 1/2 percent seven percent and 7.3
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percent for the three-month nine month 15 month and 21 month period we are also
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aware that on the last payment date six month LIBOR price was 6.2 percent what
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is the value of this swap so that's what we have to solve there are two methods
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to do this calculation one calculates the equivalent bond values one fixed and
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one floating and takes the difference between these present values the other
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method involves calculating the value of the swap as a portfolio of fr-s our
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forward rate agreements for each of the upcoming payment periods and then taking
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the present value of the differences in fixed versus floating cash flows from
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each upcoming payment period on screen right now you can see the calculations
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of the bond valuation method which is what we're going to work through first
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the value to the receive fixed counterparty is the fixed bond valuation
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- the floating bond valuation we concede that the swap is worth minus 4.2 -
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million dollars. The opposing counterparty will have the opposite
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value so they will see the value as plus four point two two million dollars so
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what have we done in there we just put together a table of the expected cash
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flows for each bond and the timing of the payments remaining on the swap the
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fixed payments are easy enough they're just two and a half million dollars each
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period and because we're valuing this as if it was a bond a hundred and two point
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five million dollars at the last payment we use the LIBOR rates from the question
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to present value those cash flows so the column labeled discount factor is just e
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to the discount rate which in the first payment period three months is 6% so
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that is e to the minus 6% times three over 12 which is three months out of the
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twelve months in a year that gives us 0.9851.
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We do the same calculation subbing in the different applicable interest rates
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and holding periods and we calculate all of the different discount rates we then
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just multiply those discount rates by the 2.5 million dollar cash flows and
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the final 102.5 million dollar cash flow, sum them all up and
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that is the value of the fixed-rate bond which you can see in our example that
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it's $97.3419 million the next step is to present
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value the floating rate bond. How do we do that? Well a basic semi-annual coupon
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floating rate bond has the coupon indexed to LIBOR each coupon date the
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coupon is equal to the par value of the note, times one-half the six-month rate
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quoted six months earlier at the beginning of the coupon period. So each
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coupon is based on the previous six month rate only the next coupon is known
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at the current date the later ones are random thus a floating rate bond is
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always work par on the next coupon date with certainty and that's just because
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we have a floating rate being discounted at a floating rate so it just comes to
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par value for the bond so it's actually quite easy to price a floating rate bond
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all we have to do is discount the upcoming coupon which we know with
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certainty at the appropriate discount rate now you'll note that in the
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question the very last line in the question said we are also aware that the
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last payment date six month LIBOR price was 6.2%t so to price
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that floating rate bond we know that that payment is coming in three months
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so we must PV it or present value it at the three month interest rate after
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which the bond will be worth par so that's all that's happening in that
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column that's labeled floating bond value we have a hundred million plus a
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hundred million times six point two percent over two as it's a semi-annual
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coupon giving us $103.1 million. We then multiply that by the
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discount factor which we calculated earlier as 0.9851 and that gives us
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101.565 million dollars the value to the receive fixed counterparty
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is the fixed bond valuation minus the floating point value asian we can then
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see that the swap is worth -4.22 million dollars. The
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opposing counterparty will have the opposite value so that's it that's all
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we have to do to price our swap next let's look at valuing the same swap but
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this time using a different method we're going to the swap as a portfolio of F or
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a's which stands for forward rate agreement we draw up a table with a lot
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of the same elements in it as in the last table as you can see the fixed cash
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flows are the same the time periods and discount factors are the same and
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they're calculated in the same method the first floating cash flow we know in
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advance and the remaining ones are calculated as shown in row two where
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we're taking the F for a continuously compounded and converting it into an F
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or a semi annually compounded in the next column we then work out the
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floating cash flows subtract them from the fixed cash flows multiplied that by
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the discount rates to get the present value of the net cash flows we sum up
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the present values of the net cash flows and get minus four point two two million
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dollars the same as the bond method that we just did earlier if you're having
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difficulty with that method you should watch my video from a few days ago on
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forward rate agreements which will explain the idea of forward rate
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agreements to you so that's it the two easiest ways to value a swap you should
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probably just learn off one method the one that you find easiest remember that
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all we're doing here there's nothing complicated happening
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we're just present valuing two cash flow and looking at the difference between
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them and that's how we value a swap if you can price a bond you can price a
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swap I haven't yet done any videos on bond
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valuation maybe I will at some point but if you're having difficulty with bond
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valuation you can probably just google it and there's a lot of good information
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that you can find online you've made it to the end of the video and the rules of
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YouTube clearly state that you have to hit the like button, so I'll wait here
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while you do that... Feel free to ask any questions in the comment section below.
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Subscribe if you'd like to see more content like this in the future and do
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hit the bell button which is right next to the subscribe button if you wish to
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be notified every time I release a new video. I'm reaching the end of my daily
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uploads and I'm shortly going to move to releasing just one video per week. Have a
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great day and see you guys again soon. Bye.
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you