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PREMIUM Khanewala
Who
is a Premium Khanewala?
In India, options have
existed since many years and Indian options market has its own dictionary.
Option writers are typically called as Khanewalas,
and Option buyers are known as Laganewalas.
The import is that Option writers eat away the premiums they earn,
while Option buyers apply their funds towards purchasing possibly valuable
rights of appreciation or depreciation in stock prices.
Players who consistently
write Options and believe in eating up premiums most of the time are known
as Khanewalas.
Is
that not a high risk proposition?
Yes, that is a high risk
proposition, but some players like risk, can handle risk and have the
knowledge and wherewithal to hedge their positions if risk rises beyond
acceptable levels. For such players, premium khana
is an exciting lunch.
How
are premiums determined and what level of premiums can be exciting for
such players?
One of the key
determinant of Option prices is the volatility in share prices. If prices
are volatile, Option prices tend to move higher. Further, if the market is
trended and most players are of the opinion that market is moving up, then
demand for calls will rise. When demand rises, buyers will be willing to
pay a higher Option price resulting in higher implied volatility levels.
When call volatility levels rise, put prices also rise sympathetically.
What
is meant by volatility and how can prices of options rise in a volatile
market and also in a trended market?
Yes, it does appear that
Option prices react by moving up in rather dissimilar situations, viz
one when the market is volatile and two when the market is
trended. Let us understand volatility. If market is moving up and down, up
and down severely, volatility levels will go up. In such a situation,
option prices will also be higher.
Buyers of options are
likely to gain more if prices move up or down (up for call buyers and down
for put buyers). Hence, they are likely to pay more premium causing a rise
in prices.
If the market is trended,
most players will look for further movement in the direction of the trend
and hence be willing to pay higher for options in that direction.
Why
should put prices rise if call prices rise?
There is a basic put call
parity equation. As per text books on the subject, cash market prices are
taken to define this equation. However, I believe text books adopt that
approach because stock futures are not available (or till recently were
not available in most developed countries). In India, this put call parity
equation can be defined as under:
Strike
Price + Call Value Put Value = Futures Price
This should be true. For
example if Satyam 220 strike call is available for Rs 9 and put for Rs 12,
then Satyam Futures price should be Rs 217 (220 + 9 12).
If
that is not so, what will happen?
If that is not so, an
arbitrage opportunity will arise and prices will start moving in such a
way that the above equation becomes valid. For example, if Satyam is
available not at Rs 217 but at Rs 214, then arbitrageurs will buy the
right hand side of the equation and sell the left hand side of the
equation.
That is, they will take
the following actions:
-
Buy Satyam Futures at
Rs 214
-
Sell Satyam Calls at
Rs 9
-
Buy Satyam Puts at Rs
12
-
Net Cash outflow on
day of transacting Rs 3
By doing so, they would
have made a risk free profit of Rs 3.
How
will that be achieved? Satyam could move to say Rs 240 by the close of the
month or Rs 180 by the close of the month.
Let us examine the two
situations closely. Suppose Satyam moves to Rs 240, what is the payoff?
-
Satyam Futures
Profit of Rs 26 (240 closing price minus 214 cost)
-
Satyam Calls
Payout of Rs 20 (240 closing price minus 220 strike price)
-
Satyam Puts No
payout (Satyam closes above 220)
-
Net Cash Inflow
Rs 6
-
Net Cash Outflow on
Day of transacting Rs 3
-
Hence, Net Profit
Rs 3
On the other hand, if
Satyam moves to Rs 180, what is the payoff?
-
Satyam Futures
Loss of Rs 34 (180 closing price minus 214 cost)
-
Satyam Calls No
Payout (Satyam closes below 220)
-
Satyam Puts
Receipt of Rs 40 (220 Strike minus 180 Closing)
-
Net Cash Inflow
Rs 6
-
Net Cash Outflow on
Day of transacting Rs 3
-
Hence, Net Profit
Rs 3
Thus, irrespective of
wherever Satyam moves, the arbitrageur will make a profit of Rs 3.
What
if the left hand side of the equation is lower?
Consider a situation
where call and put prices are the same as above, but Satyam futures are
quoting at Rs 219.
In this case, the
arbitrageur will buy the left hand side of the equation and sell the right
hand side. That is, he will take the following actions:
-
Buy Satyam Call at Rs
9
-
Sell Satyam Put at Rs
12
-
Sell Satyam Futures
at Rs 219
-
Net Cash Inflow on
Day of transacting : Rs 3
What
is the assured profit and how do we establish it if Satyam moves to say Rs
245 or Rs 195 at close of the month?
The assured profit is Rs
2 (as per the equation Satyam Futures should have quoted at Rs 217, but it
is actually quoting at Rs 219 hence the difference is Rs 2).
If Satyam closes at Rs
245, let us check the payoff on the last day.
-
Satyam Futures
Loss of Rs 26 (219 sale price minus 245 closing price)
-
Satyam Calls
Receipt of Rs 25 (245 closing price minus 220 strike)
-
Satyam Puts No
Payout (Satyam closes above 220 strike)
-
Net Cash Outflow
Re 1
-
Net Cash Inflow on
Day of transacting Rs 3
-
Hence, Net Profit
Rs 2
If Satyam closes at Rs
195, let us check the payoff on the last day.
-
Satyam Futures
Profit of Rs 24 (219 sale price minus 195 closing price)
-
Satyam Calls No
Payout (Satyam closes below 220 strike price)
-
Satyam Puts
Payout Rs 25 (220 strike minus 195 closing price)
-
Net Cash Outflow
Re 1
-
Net Cash Inflow on
Day of transacting Rs 3
-
Hence, Net Profit
Rs 2
What
does this establish?
The put call parity
equation establishes that call and put prices have to move together in a
disciplined manner. In any given market, if call prices shoot up (due to
trending, higher volatility, expectations of any news or any other
factor), put prices will necessarily respond.
What
are the risks in the put call parity arbitrage that we discussed above?
The first risk is
execution risk. While the computerized trading systems may show the prices
as in my example, the prices might change with fraction of a second, so
that when you actually execute you do not get the arbitrage difference as
expected. You might get slightly less or sometimes even more.
Secondly, if you have
sold calls or puts, these might be exercised sometime before expiry. In
that case, you will receive the exercise notice after the close of trading
hours. You will have to reinstate the same position in the morning
tomorrow, but by that time the scrip might have moved away. This could
result in a cost (or a gain), but in any case you face overnight risk.
Third, such arbitrages
are not easily available and you need to watch the market closely.
Fourth, such arbitrages
might not be available in large volumes. Hence, if you a large player, you
might find not enough opportunities on a regular basis.
What
does the Khanewala desire?
The Khanewala
desires that he should sell options when volatility levels are high so
that his premium income is maximized. He will be delighted if volatility
levels fall after he completes his sales.
Most Khanewalas look at
Option prices in a simplistic manner taking the Option prices as a
percentage of the stock prices. They might for example comment that Satyam
calls are generating 4% premium per month and this is interesting. Some
people equate this with earning interest on a principal so to say and a 4%
monthly return might translate into a 48% annual return which is very
exciting considering other investment avenues available today. Obviously,
this is a simplistic method of looking at premiums but is done commonly.
How
is this simplistic percentage return related to volatility?
If we run a simulation on
Black Scholes, taking a 30 day period to expiry and a zero percent
interest rate, the following interesting pattern emerges:
|
Implied
Volatility %
|
Option
Premium % to Stock Price
|
Incremental
Option Premium %
|
|
15%
|
1.72%
|
|
|
20%
|
2.29%
|
0.57%
|
|
25%
|
2.86%
|
0.57%
|
|
30%
|
3.43%
|
0.57%
|
|
35%
|
4.00%
|
0.57%
|
|
40%
|
4.57%
|
0.57%
|
|
45%
|
5.14%
|
0.57%
|
|
50%
|
5.71%
|
0.57%
|
|
55%
|
6.28%
|
0.57%
|
|
60%
|
6.85%
|
0.57%
|
Thus, the simplistic
Option Premium increases by 0.57% for every 5% point increase in Implied
Volatility.
What
is Implied Volatility?
In the Black Scholes
model, Option prices are based on six variables:
-
Stock Price
-
Strike Price
-
Volatility
-
No of Days to expiry
-
Interest Rate
-
Dividends
The current Option price
would reflect a certain level of Volatility automatically. This level of
Volatility is said to implied in the Option price. For example, if
Satyam is at Rs 217 and the 220 Call trades at Rs 9 when there are 30 days
to expiry with a Interest rate of zero percent and a dividend of zero,
then what is the volatility level which results in the price being Rs 9?
If you run it on the Black Scholes calculator, you find the volatility is
42%. This 42% is the Implied Volatility.
Is
there any other kind of Volatility?
Yes, the volatility
actually shown by the stock in the past is called Historical Volatility
(also referred to as Statistical Volatility by some people). This is based
on the actual movement in the stock over a certain period of time. For
example, you could take up the movements over the past ten days and work
out the volatility level.
Technically, the steps
involved are as under:
-
Put down the stock
prices in an Excel column
-
Work out the daily
change in prices (todays price minus yesterday)
-
Express the daily
change in percentage terms (Daily change upon yesterdays price)
-
Work out the standard
deviation of this daily change percentage column
The resulting figure is
the ten day volatility of Satyam.
Is
there a relationship between the two?
Yes, there would be a
vague positive correlation between the two indicating that if Satyam has
been volatile in the recent past, the market will expect it to stay
volatile in the short term and hence options will be quoting higher. On
the other hand, if Satyam has been rather dull in the recent past (ten
days in our example), market will expect no great moves immediately and
hence option premiums will drift downwards.
However, if some news is
expected, market will start factoring this into the premium and you may
well find that implied volatility levels are rising inspite of dull
historical volatilities. Sometimes, inside information may be acting in
the market as a result of which implied volatilities might suddenly rise.
This can be a pointer to
news and can be acted upon if you are active in the market.
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