Equity Asian Option
Table of Contents
An equity Asian option pays on the averaged price of an equity
underlying over a set period. The averaging smooths the payoff. ORE
models it with the trade type EquityAsianOption. This note records
the domain grounding, as ORE documents it in its product catalogue.
1. Identifiers
What a trader books it as, and what to grep for. The codes are the trade type catalogue's, which is what the database enforces.
| Field | Value |
|---|---|
| Full name | Equity Asian Option |
| Short name | Equity Asian Option |
| ORE Studio product code | EquityAsianOption |
| Asset class | equity |
| Family | Option |
| ORE trade data node | EquityAsianOptionData |
| ORE documentation | eq_asianoption.tex |
2. Summary
An equity Asian option is a path-dependent option whose payoff depends
on the averaged price of an equity underlying over a pre-set period.
The average is arithmetic by default and can be geometric. A fixed-
strike form compares the average to a strike. A floating-strike form
compares the final price to the average. The container node is
EquityAsianOptionData. It holds one OptionData sub-node and an
ObservationDates schedule. The container node includes the strike,
quantity and underlying.
3. Detail
3.1. What it is
ORE defines the product as follows:
An Equity Asian Option is a path-dependent option whose payoff depends upon the averaged price of an Equity underlying over a pre-set period of time.
Source: ORE User Guide, Products catalogue, eq_asianoption.tex.
3.2. In plain terms
An Asian option looks at the average price instead of the final price. Daily fixings over the observation period build the average. A customer who fears a price spike on one day prefers the average. The payoff is harder to manipulate and cheaper than a vanilla option.
3.3. How it works in ORE
The EquityAsianOptionData node is the trade data container for the
EquityAsianOption trade type. It has one OptionData trade
component sub-node plus elements specific to the equity Asian option.
StrikeData holds the strike in Value and the currency of the
underlying and the strike in Currency. Quantity is the number of
underlying equities. The node takes one Underlying element with
Type set to Equity. The OptionData fields set LongShort,
OptionType, PayoffType and the exercise date. PayoffType must be
Asian or AverageStrike. The first identifies a fixed-strike Asian
payoff and the second a floating-strike payoff. PayoffType2 is
optional and takes Arithmetic or Geometric. It defaults to
Arithmetic. Exactly one ExerciseDate must be given. Premiums
can represent deterministic option premia. Settlement is optional
and defaults to the exercise date. ObservationDates holds the Asian
observation period as a rules-based or dates-based schedule.
3.4. Mathematical notes
The payoff is Payoff = Quantity x MAX(omega x (A(0,T) - K), 0). A(0,T)
is the arithmetic average of the underlying equity spot price over
the Asian observation period from start 0 to end T. K is the equity
strike price. Omega is 1 for a call option and -1 for a put option.
A geometric average is available through PayoffType2. The averaging
reduces the volatility that reaches the payoff.
3.5. What moves its value (static sensitivities)
- The spot price of the underlying equity.
- The implied volatility of the underlying.
- The strike and the exercise date.
- The observation schedule and its remaining fixings.
- The interest rates and dividends of the underlying.
The average lags the spot. A move near the end of the period moves the average more than a move near the start.
3.6. How the profile ages (dynamic sensitivities)
Each observation date adds a fixing to the average. Early fixings become fixed parts of the average. As the period fills, the average stiffens and the option's effective delta falls. Near the final observation the average is almost known and the option value approaches its settlement value.
3.7. Why a customer would want it
A customer who receives or pays a periodic equity price, such as an average-priced buyback, wants an option on that average. The Asian payoff matches the exposure and costs less than a vanilla option of the same expiry. In ORE Studio a customer books equity Asian options to value them and run sensitivities on the ORE engine.
3.8. Example
ORE's catalogue shows a long call on the average of the S&P 500 index over daily observations:
<Trade id="EquityAsianOption"> <TradeType>EquityAsianOption</TradeType> <Envelope> <CounterParty>CPTY_A</CounterParty> <NettingSetId>CPTY_A</NettingSetId> <AdditionalFields /> </Envelope> <EquityAsianOptionData> <Quantity>100</Quantity> <Currency>USD</Currency> <StrikeData> <Value>3100</Value> <Currency>USD</Currency> </StrikeData> <Underlying> <Type>Equity</Type> <Name>RIC:.SPX</Name> <Currency>USD</Currency> </Underlying> <OptionData> <LongShort>Long</LongShort> <OptionType>Call</OptionType> <PayoffType>Asian</PayoffType> <PayoffType2>Arithmetic</PayoffType2> <ExerciseDates> <ExerciseDate>2020-07-15</ExerciseDate> </ExerciseDates> <Premiums> ... </Premiums> </OptionData> <Settlement>2020-07-20</Settlement> <ObservationDates> <Rules> <StartDate>2019-12-27</StartDate> <EndDate>2020-07-06</EndDate> <Tenor>1D</Tenor> <Calendar>US</Calendar> <Convention>F</Convention> <TermConvention>F</TermConvention> <Rule>Forward</Rule> </Rules> </ObservationDates> </EquityAsianOptionData> </Trade>
Source: ORE User Guide, Products catalogue, eq_asianoption.tex,
listing Equity Asian Option data.
4. See also
- Knowledge — the hub of all knowledge notes, with the alphabetical product run.
- Wikipedia: Asian option. This note follows its general definition.
- ORE User Guide, Product catalogue: products.tex, which inputs eq_asianoption.tex. The upstream project is OpenSourceRisk/Engine.