Equity Digital Option
Table of Contents
An equity digital option pays a fixed amount or nothing, decided by
the equity spot at expiry. ORE models it with the trade type
EquityDigitalOption. 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 Digital Option |
| Short name | Equity Digital Option |
| ORE Studio product code | EquityDigitalOption |
| Asset class | equity |
| Family | Option |
| ORE trade data node | EquityDigitalOptionData |
| ORE documentation | eq_digitaloption.tex |
2. Summary
An equity digital option is an option whose payout is either zero or a
fixed predetermined amount. The payout is cash-or-nothing. It depends
on whether the underlying equity spot expires in the money at the
expiration date. The product has European exercise with payout at
expiry. The buyer pays a premium to the seller. The container node is
EquityDigitalOptionData. It holds one OptionData sub-node plus the
strike, payoff amount and quantity.
3. Detail
3.1. What it is
ORE defines the product as follows:
An Equity Digital Option is an option whose payout is either zero or a fixed predetermined amount (Cash-or-Nothing). Payout depends on whether the underlying Equity spot rate expires in-the-money at the expiration date.
Source: ORE User Guide, Products catalogue, eq_digitaloption.tex.
ORE adds the exercise terms as follows:
Equity Digital Options have European exercise with payout at expiry. The buyer of a Equity Digital Option pays a premium to the seller.
Source: ORE User Guide, Products catalogue, eq_digitaloption.tex.
3.2. In plain terms
A digital option is a binary bet on a share price. If the price ends on the right side of the strike, the buyer receives the fixed payoff amount. If not, the buyer receives nothing. There is no middle ground. The option is a pure view on the direction.
3.3. How it works in ORE
The EquityDigitalOptionData node is the trade data container for the
EquityDigitalOption trade type. It has one OptionData sub-node
plus elements specific to the equity digital option. LongShort
names the side. OptionType takes Call or Put. A call is in the
money when the underlying equity price is above the strike. A put is
in the money when it is below. The Style is European only. Exactly
one ExerciseDate must be given. Premiums is optional and holds the
premium amounts paid by the buyer. Strike is the option strike per
unit of the underlying, expressed in the currency of the underlying
equity. PayoffCurrency is the currency of the payoff amount and must
be consistent with the currency of the underlying equity spot.
PayoffAmount is the fixed payoff amount per unit of underlying,
expressed in the payoff currency. The underlying comes from Name or
an Underlying node. Quantity is the number of units of the
underlying covered by the transaction.
3.4. Mathematical notes
The payoff per unit is the fixed PayoffAmount when the option is in
the money at expiry, and zero otherwise. For a call the condition is
the spot above the strike at expiry. For a put it is the spot below
the strike. The total payout scales with the quantity. The value is
the discounted probability of finishing in the money times the payoff
amount.
3.5. What moves its value (static sensitivities)
- The spot price of the underlying equity and its distance to the strike.
- The implied volatility of the underlying.
- The strike and the expiry.
- The interest rates and dividends of the underlying.
Near the strike the digital is most sensitive to the spot and to volatility. The payout does not grow with the depth of the finish in the money.
3.6. How the profile ages (dynamic sensitivities)
The digital decays toward its settlement as expiry approaches. Its value is the discounted probability of the payoff event. With the spot far from the strike, the payout becomes almost certain or almost worthless. At expiry the spot decides the payoff and the option settles.
3.7. Why a customer would want it
A customer with a fixed view on a share price can take a binary payout. The digital pays a known amount for a known premium. It also builds spreads and structured payouts where a fixed cash amount is needed. In ORE Studio a customer books equity digital options to value them and run sensitivities on the ORE engine.
3.8. Example
ORE's catalogue shows a long call digital on the S&P 500 index that pays 1000 per unit above strike 3300:
<EquityDigitalOptionData> <OptionData> <LongShort>Long</LongShort> <OptionType>Call</OptionType> <Style>European</Style> <ExerciseDates> <ExerciseDate>2027-02-26</ExerciseDate> </ExerciseDates> ... </OptionData> <Strike>3300</Strike> <PayoffCurrency>USD</PayoffCurrency> <PayoffAmount>1000</PayoffAmount> <Name>RIC:.SPX</Name> <Quantity>1000</Quantity> </EquityDigitalOptionData>
Source: ORE User Guide, Products catalogue, eq_digitaloption.tex,
listing Equity Digital Option data.
4. See also
- Knowledge — the hub of all knowledge notes, with the alphabetical product run.
- Wikipedia: Binary option. This note follows its general definition.
- ORE User Guide, Product catalogue: products.tex, which inputs eq_digitaloption.tex. The upstream project is OpenSourceRisk/Engine.