Understand strategy selection by view & IV — Stock-Market notes

WHY does IV matter as much as direction?

Formula IV Rank — deriving the "high vs low" number

We need a way to say "IV is high for this stock". Raw IV of 40% is huge for a bond ETF but tiny for a meme stock. So normalise against the stock's own 1-year range.

Let over the past year:

$IV_{now}$ = current implied volatility
$IV_{min}, IV_{max}$ = lowest/highest IV in the window

We want a number in $[0,1]$ that is $0$ at the floor and $1$ at the ceiling. The natural linear map is: $\text{IV Rank} = \frac{IV_{now} - IV_{min}}{IV_{max} - IV_{min}}$ Why this form? Subtract the floor so the bottom of the range maps to $0$ ; divide by the span so the top maps to $1$ . It's just a min–max rescaling.

IV Rank $> 0.5$ → "high IV" → lean toward selling premium (net short options).
IV Rank $< 0.5$ → "low IV" → lean toward buying premium (net long options).

HOW to combine the two axes

Figure — Understand strategy selection by view & IV

Formula The selection matrix (learn this cold)

View \ IV	Low IV (buy premium)	High IV (sell premium)
Bullish	Long Call / Bull Call (debit) spread	Short Put / Bull Put (credit) spread
Bearish	Long Put / Bear Put (debit) spread	Short Call / Bear Call (credit) spread
Neutral	Long Straddle/Strangle (buy vol)	Iron Condor / Short Straddle (sell vol)

Why the diagonal symmetry? Bullish-low-IV and Bullish-high-IV both profit if price rises, but the first is long vega (wants IV up) and the second is short vega (wants IV down). Same view, opposite volatility bet.

Worked examples

Common mistake Steel-man the classic errors

"I'm bullish, so I always buy calls." Why it feels right: Long calls are the simplest way to express upside and have capped risk. Feels clean. The fix: If IV Rank is high, the call is overpriced; IV crush can hand you a loss on a stock that rose. In high IV you sell premium (short put / bull put spread) to make the vol work for you.

"High premium = high reward, so selling is always better." Why it feels right: Fat credit looks like free money. The fix: High premium means high expected movement — the market is pricing large risk. Undefined-risk sells (naked options) can blow up. Use defined-risk spreads (iron condor, credit spread) so a tail move doesn't ruin you.

"IV of 40% is high." Why it feels right: 40% sounds big. The fix: "High" is only meaningful vs the stock's own history — use IV Rank/Percentile, not the raw number.

Recall Feynman: explain to a 12-year-old

Buying an option is like buying an umbrella. The view is your guess whether it'll rain (price up/down). The IV is how much the shop charges for umbrellas today. If everyone's scared of a storm, umbrellas are expensive (high IV) — smarter to be the shop selling umbrellas. If skies look clear and umbrellas are dirt cheap (low IV), you buy one because it barely costs anything. So you always ask two questions: "Will it rain?" AND "Are umbrellas cheap or pricey right now?"

Flashcards

What two independent axes define every option strategy?

Direction (market view) and Volatility (IV regime — cheap vs expensive).

Formula for IV Rank

\text{IV Rank} = \dfrac{IV_{now}-IV_{min}}{IV_{max}-IV_{min}}

over a look-back window (usually 1 year).

IV Rank of 0.85 means what action bias?

High IV → be a net SELLER of premium (short vega, collect theta).

IV Rank of 0.15 means what action bias?

Low IV → be a net BUYER of premium (long vega, cheap leverage).

Bullish + Low IV → best structure?

Long call / Bull Call debit spread (long vega, cheap leverage).

Bullish + High IV → best structure?

Short put / Bull Put credit spread (short vega, collect fat premium).

Bearish + High IV → best structure?

Short call / Bear Call credit spread.

Neutral + High IV → best structure?

Iron Condor or Short Straddle (sell vol, profit from IV crush + theta).

Neutral + Low IV → best structure?

Long Straddle/Strangle (buy vol, profit from expansion).

What is IV crush and why does it hurt long calls?

A sharp drop in IV after an event; it lowers option prices via negative vega, so a long call can lose money even if the stock rose.

Why is raw IV (e.g. 40%) not enough to call IV "high"?

"High" is relative to the stock's own historical range — use IV Rank/Percentile.

Same bullish view, low vs high IV — what flips?

The sign of vega: low IV → long vega (want IV up); high IV → short vega (want IV down).

Why prefer defined-risk credit spreads over naked options in high IV?

High premium signals large expected moves; defined-risk spreads cap tail-risk loss.

Connections

Implied Volatility — the input that defines the IV axis.
IV Rank vs IV Percentile — how to measure "high vs low".
Option Greeks — Vega — why buying/selling reacts to IV changes.
Option Greeks — Theta — time decay favouring premium sellers.
Bull Call Spread / Bull Put Spread — bullish structures by IV.
Iron Condor / Long Straddle — neutral structures by IV.
IV Crush — the earnings trap this note protects against.

Concept Map

Hinglish (regional understanding)

Intuition Hinglish mein samjho

Dekho, option strategy chunne ke liye sirf "market upar jaayega ya neeche" sochna kaafi nahi hai. Do cheezein ek saath dekhni padti hain: View (direction — bullish/bearish/neutral) aur IV (implied volatility — options abhi mehenge hain ya saste). Yeh dono alag-alag axes hain, aur dono ka combination decide karta hai ki exactly kaunsi strategy lagani hai.

Simple rule yaad rakho: IV high hai to premium bech do (sellers ban jao), IV low hai to premium khareedo (buyers ban jao). Kyunki high IV ka matlab hai market bada move price kar raha hai — us fat premium ko collect karna smart hai, aur event ke baad "IV crush" hone par option ka daam gir jaata hai jo seller ke favour mein hai. Low IV mein options sasta milta hai, to khareedna cheap leverage deta hai. Ek galti jo har beginner karta hai: "bullish hoon to hamesha call khareed lo" — par agar IV high hai, to call overpriced hai, aur stock upar jaane ke baad bhi IV crush se tumhaara call loss mein aa sakta hai! Isliye high IV mein bullish view ke liye short put ya bull put spread better hai.

IV "high" ya "low" kaise pata karein? Raw number (jaise 40%) dekh ke nahi — har stock ka apna range hota hai. IV Rank use karo: $(IV_{now}-IV_{min})/(IV_{max}-IV_{min})$ over last 1 year. Agar yeh 0.5 se upar hai to high IV (bech do), 0.5 se neeche to low IV (khareed lo).

Bas matrix yaad rakho: delta ko apne view se match karo, aur vega ko apne IV se match karo. Neutral view mein bhi yahi logic — low IV mein long straddle (vol khareedo), high IV mein iron condor (vol becho). Yeh do-axis soch tumhe overpaying aur IV crush ke trap se bacha legi.

WHY does IV matter as much as direction?

HOW to combine the two axes

Worked examples

Flashcards

Connections

Concept Map

Hinglish (regional understanding)

Test yourself — Options Strategies

Connections