Derivatives Foundation interview preparation
The full derivatives syllabus from no-arbitrage pricing through the Greeks, the volatility surface, swaps, CDS and clearing, plus the Indian index-options market. Every question is either traced to a named firm from a public candidate report, or tagged at desk level when we could not trace it - we do not invent attributions.
100 questions, mapped to the firms that asked them
- Questions
- 100
- Traced to a firm
- 29
- Firms
- 19
- Updated
- September 2026
043Explain a covered call. When is it the right trade and what is the real risk?Wealth managementIndian broking
Say this
Long the stock, short a call against it. You collect premium and cap your upside at the strike. It is the right trade when you are mildly bullish to neutral and would be happy to sell at the strike. The real risk is not the stock falling — it is that you have sold the upside tail, which is where most of an equity's long-run return lives.
Then walk it
- Payoff: you keep the premium plus any appreciation up to the strike, and above that you deliver the stock. Below, you take the full downside less the premium you received.
- So it is the same payoff shape as a short put at that strike — the synthetic equivalence falls straight out of put-call parity. Anyone selling covered calls should know they are running a short-put risk profile.
- When it works: a range-bound stock, a high implied volatility that you think is overpriced, or a genuine intention to exit at the strike. Overwriting is also a legitimate income overlay for a mandate that has to generate yield.
- The honest risk: your worst outcome is being right about direction and wrong about magnitude. The stock triples, you delivered at plus 10 percent, and you have converted an asymmetric long-run payoff into a capped one. Equity index returns are driven by a small number of very large up moves, so capping them is expensive.
- There is also a tax and path problem in practice: getting called away triggers a realisation you may not have wanted, and rolling the short call up in a rally locks in a loss on the option leg while the stock leg is unrealised.
- Where I would actually use it: on a position I already intended to trim, at a strike that equals my target exit price, with the premium as a sweetener. Framing it as income on a core holding you want to keep forever is the mis-sale, and it is a very common one in retail advisory.
Where candidates lose it
Selling it as free income. The interviewer will ask what happens in a 40 percent rally, and the answer that gets respect is that a covered call is a short put in disguise and you have sold the fat right tail. Say the synthetic equivalence out loud.
Expect next
- What position is a covered call equivalent to?
- The stock rallies 50 percent. What do you do?
- Would you recommend a covered call programme to a long-term retirement portfolio?
045Straddle or strangle — how do you choose?Prop trading firmsVolatility trading
Say this
Both are pure volatility positions with no directional view. A straddle buys the at-the-money call and put, so you pay more and get maximum gamma right where spot is. A strangle buys out-of-the-money strikes, so it costs less and needs a bigger move, but it gives you more exposure to the tails per rupee spent.
Then walk it
- Straddle: highest gamma and vega concentrated at the strike, highest premium, highest theta bleed. You want it when you expect a move and you expect it soon, and when you will delta hedge to harvest the path.
- Strangle: cheaper, wider break-evens, lower theta per day. You want it when you expect a large move but are unsure of timing, or when you specifically believe the wings are underpriced relative to the body.
- The wings-versus-body choice is a skew and kurtosis view, not just a cost decision. Long strangle, short straddle is a butterfly — that is a pure bet that the distribution is fatter-tailed than the smile implies.
- Break-even arithmetic: a 4.5 percent straddle needs a 4.5 percent move by expiry. A strangle costing 2 percent with strikes 5 percent out needs a 7 percent move. So the strangle wins only in the big-move scenarios and loses in the moderate ones.
- In practice the choice is often dictated by liquidity and margin. In Indian index options the out-of-the-money weekly strikes are extremely liquid and cheap in absolute rupee terms, which is why retail gravitates to strangles — and why the margin framework treats short strangles more punitively after the 2020 peak-margin reforms.
- The limitation for both: if you are not delta hedging, you are betting on the terminal price, not on volatility, and a stock that swings wildly and closes flat pays you nothing. State which trade you are actually putting on.
Where candidates lose it
Framing it purely as 'strangle is cheaper'. The real distinction is where you want your gamma and whether your view is about the body or the tails of the distribution. And name the unhedged-versus-hedged difference, because otherwise you are describing a direction bet.
Expect next
- Long strangle against short straddle — what have you built and what is the view?
- Which would you rather own into an earnings print?
- What does margin treatment do to the choice in India?
047Why would you buy a call spread instead of just buying a call?Indian brokingWealth management
Say this
Because you have a target, not an unbounded view. Selling the higher strike funds a chunk of the premium, cuts your theta and vega, and raises your probability of profit — at the cost of capping the payoff. If your thesis is 'up 8 percent by June' rather than 'up a lot', the spread is the honest expression of it.
Then walk it
- Mechanics: buy the 100 call for 5, sell the 110 call for 2, net cost 3, maximum payoff 10 at or above 110. You have turned a 5-point bleed into a 3-point bleed and a 7-point maximum gain.
- The Greeks get tamer. Vega and theta both shrink because you are long one option and short another, so a fall in implied volatility hurts far less. If you are worried about buying expensive volatility, the spread protects you against that.
- Probability of profit rises because the break-even is nearer. You need the stock at 103 rather than 105, which on a one-month view is a meaningful difference.
- It is also a skew trade whether you intend it or not. In an equity index the calls you sell are cheaper in implied terms than the calls you buy, so a call spread is a mildly unattractive skew position. Put spreads in equities work the other way — you sell the expensive wing.
- Where it goes wrong: the payoff is capped, so a takeover or a squeeze that takes the stock to 150 pays you the same 7 as a move to 110. If your thesis has a fat-tail scenario in it, the spread is the wrong structure.
- And near expiry a spread can be awkward to close — you may have to trade out of two legs in thin markets, or face assignment on one leg and not the other. The neat payoff diagram assumes you hold to expiry, and in practice the exit cost is real.
Where candidates lose it
Just saying it is cheaper. Cheaper is not a reason on its own — you paid less and you get less. The answer is about matching the structure to the shape of your view, plus the reduction in vega if you think implied volatility is high. Mention the skew direction to sound like a trader.
Expect next
- How does the skew affect a call spread versus a put spread in equities?
- What if the stock gets taken over at a 50 percent premium?
- Which leg would you close first if you wanted out early?
048Explain a butterfly and an iron condor, and tell me what view each expresses.Prop trading firmsVolatility trading
Say this
Both are short-volatility, range-bound structures with capped losses. A butterfly is short the body and long the wings — sell two at-the-money options, buy one either side. An iron condor is the same idea with a gap in the middle: sell an out-of-the-money put and call, buy further-out ones as protection. The view is that the underlying stays in a range and that implied volatility is too high.
Then walk it
- Butterfly payoff: maximum profit if the underlying pins the middle strike at expiry, losses limited to the width less the credit. It has the highest payoff concentration of any standard structure, which is why it is the expiry-day trade of choice.
- Iron condor: a wider profit plateau between the two short strikes, smaller maximum profit, higher probability of ending inside the range. It is the same trade with less precision required about where the underlying lands.
- Read a long butterfly as short kurtosis. You are selling the body and buying the wings, which is a statement that the distribution is thinner-tailed than the smile implies. That is why butterfly prices are how FX desks quote the curvature of the smile.
- Both are short gamma and short vega in the middle, so they make money from time passing and from implied volatility falling. Both have their worst outcome on a large move in either direction, which is bounded by the long wings.
- Where they actually get used in India: Nifty and Bank Nifty weekly expiries, because the short-dated theta is large and the structures are margin-efficient once the wings are in place. That is also where they are most frequently oversized by retail traders.
- The real risk is the one the payoff diagram hides: the position is fine at expiry and can be badly underwater before it. A move to the edge of the range mid-life produces a mark-to-market loss and a margin call, and traders get closed out of positions that would have been profitable if held. Capped loss is not the same as capped margin.
Where candidates lose it
Drawing the payoff diagram and stopping. Two things earn the answer: naming the butterfly as a curvature or kurtosis trade, and pointing out that a capped-loss structure can still force you out early through margin. That second point is where retail traders in weekly options actually lose.
Expect next
- Why do FX desks quote the smile using butterflies?
- Which is safer for a retail trader, and does the margin agree with you?
- What happens to your iron condor two weeks in with spot at the short put strike?
049What is a calendar spread and what are you really trading?Volatility tradingMarket making
Say this
Same strike, two expiries. Long the back month and short the front is a long calendar: you are long vega, short gamma, and long the term structure. What you are really trading is the slope of the volatility curve plus the difference between short-dated and long-dated realised volatility.
Then walk it
- Positioning: the front month has most of the gamma and theta, the back month most of the vega. So long the back and short the front collects theta from the front and stays long vega on the back.
- The classic use is after a volatility spike. The front month is at 60, the back at 30, so you sell the front and buy the back, betting on mean reversion in the near term rather than on the level of volatility.
- It is also an event trade in reverse. If an earnings date sits in the front expiry, the front implied is inflated by the event. Selling the front and buying the back captures the event premium if the print is quiet.
- Risks are asymmetric and this is the part to get right. Short front-month gamma means a large move immediately is very painful, because the front option's gamma dwarfs the back's. The position is long volatility in vega terms and short it in gamma terms, and those two can lose at the same time.
- Roll and pin risk at the front expiry are real operational issues. You have to manage the front leg through settlement, and if it finishes at the strike you have a pin problem on one leg of a position you intended to hold.
- The honest limitation: a calendar spread is a term-structure view, so you can be exactly right about the volatility level and lose because the curve moved in parallel rather than flattening. Calendars are best sized small and judged on the spread between the two implieds, not on either leg alone.
Where candidates lose it
Describing a calendar as 'selling time decay'. It is a term-structure trade with opposite signs on gamma and vega, and the danger is an immediate large move against short front-month gamma. Naming the post-spike mean-reversion use case shows you know why anyone puts it on.
Expect next
- Which leg holds your gamma and which your vega?
- What happens if the market gaps the day after you put it on?
- How would you use a calendar around an earnings date?
Firm tags come from public, anonymous candidate reports on Wall Street Oasis: strong signal, not sworn testimony. Firms are named as the places a question was reported, not as partners of Fin Maverick. Answers are written for this page to show how to think out loud; they are not scripts to recite.

