# Tagged Questions

A contract that gives the owner the right, but not the obligation, to buy or sell a security at a fixed price in the future.

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### Boundary Conditions for Call Spread

I was just wondering if someone could verify whether these are the two boundary conditions for a Call Spread Black-Scholes PDE. The first one I have is: $max(S_{T} - K_{1}, 0) - max(S_{T}-K_{2},0)$ ...
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### Pricing with-profit/smoothed bonus annuity using Black-Scholes

Would this be possible? Subsequently, would the pricing of such an annuity be somewhat similar to pricing a lookback option?
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### Is it possible to find / estimate the volatility surface of non-listed index options?

I have 3 QNET options (european, 2 puts, 1 call, all same expiry, different strikes) that the broker is pricing clearly off a volatility surface. Bloomberg only carries historical volatility and I ...
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### Accurately calculating Greeks for options near expiration

I understand that when a vanilla European option is near expiry, the Theta calculated from BS formula is very inaccurate and almost meaningless for practical use. However, I'm not sure if other ...
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### What does it mean when a risk reversal is near choice?

I'm currently reading Kathy Lien's 'Day Trading and Swing Trading the Currency Market' and I came across this phrase on risk reversals: "near choice". What does it mean when risk reversals are near ...
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### Solution for american perpetual put

I have been attempting an exercise in which I have to determine the value of an american perpetual put, $P$ in terms of the asset value $S$. The solution to the exercise says: When $S>S_f$ (the ...
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### How to hedge a barrier option with vanilla options?

I want to hedge a barrier option, say a knock-out call with strike K and barrier B out-of-the-money. My idea was to start from the payoff diagram of this option, and try to accomodate it with vanilla ...
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### Taleb Modified Delta

How does one go about calculating the modified delta as proposed by Taleb in his book Dynamic hedging? In his book he says its a change in the call price divided by a change in the underlying and ...
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### Construct option and stock portfolio

If a riskless security costs 100 today and will cost 120 at time T, a stock costs 50 today and will either be 70 or 30 at time T, and call options on the stock have strike price 50 expiring at time T, ...
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### The Upper Bound of an American Put Option

I have just read the following paragraph (in bold) and have a question on the upper bound of an american put option: http://www.sharemarketschool.com/option-valuation-upper-and-lower-bounds-part-...
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### Linear combination of payoffs of bull and bear spreads

Write the following payoffs as linear combination of call options with different strikes and possibly some cash and give the closed form formula for them. Attempted solution: The payoff for the bear ...
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### Link between Vega and Gamma

"The vega is the integral of the gamma profits ( ie expected gamma rebalancing P/L) over the duration of the option at one volatility minus the same integral at a different volatility...Mathematically,...
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### Calendar spreading and difference in cash and futures

"Often the calendar spreading gives rise to two different levels of gamma: a long gamma in one maturity against a short gamma in another one. This may be stable except that the two maturities might ...
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### Using limit orders or stop orders and gamma

From Dynamic Hedging by Taleb: Risk Management Rule: Option trader lore states that when long gamma, use limit orders. When short gamma, use stop orders. I cannot understand why this is and the ...
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### Why are there two expressions for the Black-Scholes hedging portfolio

I am new to derivatives pricing and am trying to understand why there are two different expressions for the Black-Scholes hedging portfolio. The first approach, used in books like Hull, stipulates ...
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### Dealers becoming synthetically short an out-of-the-money option

"When dealing with a large-size position, dealer, upon exercise, synthetically become short an out-of-the-money option." How does this work, I cannot see why this happens synthetically in ...
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### Use of cash delta vs forward delta and the mirror image rule

There has been no mention in this text of why this formula uses forward delta not cash delta. Why should have this been obvious to the reader? How can a put be delta neutral at 30%, what does this ...
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### Known future volatility and difficulty in predicting final P/L

I have started Chapter 1 of Dynamic Hedging by Taleb and it starts by saying "Even if traders knew the exact future volatility but hedged themselves (rebalanced the gamma) at discretely spaced ...