Learn weekly - monthly options expiry effects

4.4.10 · Stock-Market › When to Trade — Timing & Sessions

WHAT is happening

WHY expiry price ko move karta hai (first principles)

Intuition Hedger ko follow karo — gamma ka sign sab kuch decide karta hai

Ek hedger jo delta-neutral hai, usse spot move hone par re-hedge karna padta hai. Yeh hedging move ko shant karti hai ya fuel karti hai, yeh depend karta hai unke gamma ke sign par:

Long gamma (option BUYER hedging): jab spot barhta hai, delta barhta hai → neutral rehne ke liye woh rally mein sell karte hain; jab spot girta hai, delta girta hai → woh dip mein buy karte hain. Yeh hai buy-low / sell-high → yeh moves ko absorb karta hai aur price ko strike ke paas pin kar sakta hai.
Short gamma (option WRITER hedging): jab spot barhta hai, unka (short) delta aur zyada negative hota jaata hai → neutral rehne ke liye woh rally mein buy karte hain; jab spot girta hai woh sell karte hain. Yeh hai buy-high / sell-low → yeh move ko chase aur amplify karta hai → breakouts.
Expiry ke paas ek ATM strike par, gamma explode kar deta hai dono sides ke liye, toh jo bhi side market ke net-hedging flow mein dominate kare, woh din decide karti hai: net long gamma → pinning; net short gamma → violent trend.
Jab ek high-OI wall breached hoti hai, short-gamma hedgers ko hard chase karna padta hai → explosive gamma unwind.

Steel-man note: yeh naive claim ki "writers price ko pin karte hain" tabhi sach hoti hai jab market-maker/dealer complex net long gamma ho jo unhone warehouse kiya hai. High-OI strikes ke paas empirical pinning typically dikhata hai ki dealers un strikes par net long options hain (buy-low/sell-high), na ki writers moves amplify kar rahe hain.

Max Pain ko scratch se derive karna

Hum chahte hain woh spot price $S$ expiry par jo option buyers ko total payout minimally karti hai (equivalently, sabse zyada pain — isliye "max pain").

Step 1 — expiry par ek option ka payoff.

Strike $K$ par ek Call buyer ko deta hai: $max (S - K, 0)$ .
Strike $K$ par ek Put buyer ko deta hai: $max (K - S, 0)$ .

Yeh step kyun? Expiry par koi time value nahi bachi hoti — sirf intrinsic value rehti hai. Yahi intrinsic value ki definition hai.

Step 2 — saare strikes par total buyer payout. Maano $OI_{K}^{C}$ aur $OI_{K}^{P}$ har strike par open interest (contracts) hain. Writers ko jo total cash dena padega (per unit lot):

Pain (S) = K \sum [OI_{K}^{C} \cdot max (S - K, 0) + OI_{K}^{P} \cdot max (K - S, 0)]

Yeh step kyun? Buyer jo ek rupaya receive karta hai, woh rupaya writer ka loss hota hai. Writers (usually well-capitalized, aksar institutions) ke paas $S$ ko low-payout zones ki taraf nudge karne ka incentive/ability hoti hai.

Step 3 — minimize karo.

S_{maxpain} = ar g S min Pain (S)

Yeh step kyun? Woh strike jo total intrinsic payout minimize karta hai, wahan most options worthless mar jaate hain. Empirically, price aksar expiry mein iss level ki taraf drift karti hai (pinning) jab dealers wahan net long gamma hote hain, lekin yeh ek tendency hai, law nahi.

Figure — Learn weekly - monthly options expiry effects

HOW iske around trade karo (the 80/20)

Worked Examples

Worked example Example 1 — Max Pain Compute karna

NIFTY, sirf teen strikes OI ke saath (lots mein):

Strike $K$	Call OI	Put OI
24000	100	20
24100	60	60
24200	20	120

Test karo $S = 24100$ :

Calls pay karte hain: $100 (24100 - 24000)^{+} + 60 (0) + 20 (0) = 100 \times 100 = 10000$
Puts pay karte hain: $20 (0) + 60 (0) + 120 (24200 - 24100) = 120 \times 100 = 12000$
Pain $= 22000$ .

Test karo $S = 24000$ :

Calls: $100 (0) + 60 (0) + 20 (0) = 0$
Puts: $20 (0) + 60 (24100 - 24000) + 120 (24200 - 24000) = 60 (100) + 120 (200) = 6000 + 24000 = 30000$
Pain $= 30000$ .

Test karo $S = 24200$ :

Calls: $100 (200) + 60 (100) + 20 (0) = 20000 + 6000 = 26000$
Puts: $0$ . Pain $= 26000$ .

Minimum pain $S = 24100$ par hai (22000). Kyun? Balanced OI → agar dealers wahan net long gamma hain, toh price likely 24100 ke paas expiry mein pinned rahegi.

Common Mistakes

Recall Feynman: ek 12-saal ke bacche ko samjhao

Socho ek see-saw hai jisme beech mein ek magnet hai. Kuch players bets own karte hain aur magnet ki tarah kaam karte hain — har baar jab see-saw tipe, woh use gently center number par wapas push karte hain, toh woh stuck rehta hai ("pinning"). Doosre players ne bets bechे hain aur ulta kaam karte hain — jab see-saw tipe, woh ise aur usi direction mein push karte hain, ise wildly swing karate hain. Last day par dono effects bahut strong ho jaate hain. Kaun sa group bada hai, yeh decide karta hai ki price ek magic number par stuck rahegi ya suddenly rocket karega.

Active Recall

Options expiry kya hai?

Woh date/time jab ek contract exist karna band kar deta hai; agar ITM hai toh settle hota hai (intrinsic value hai) ya OTM hai toh worthless expire ho jaata hai.

Max Pain define karo.

Expiry par woh spot price jo option buyers ko total intrinsic payout minimize karti hai, yaani most options ko worthless expire karaati hai.

Max Pain objective likho.

S_{ma x p ain} = ar g min_{S} \sum_{K} [O I_{K}^{C} (S - K)^{+} + O I_{K}^{P} (K - S)^{+}]

Kaun sa gamma sign pinning cause karta hai?

Long gamma — hedge buy-low/sell-high hota hai, jo moves absorb/dampen karta hai aur price ko strike ki taraf pin karta hai.

Kaun sa gamma sign breakouts cause karta hai?

Short gamma — hedge buy-high/sell-low hota hai, jo moves chase aur amplify karta hai.

Kya option writers hedging price pin karti hai?

Nahi — writers short gamma hote hain (buy-high/sell-low), jo moves amplify karta hai. Pinning net long-gamma dealers/buyers se aati hai.

Expiry day par explosive move kya cause karta hai?

Ek high-OI wall breach hoti hai aur short-gamma hedgers ko chase karna padta hai (buy-high/sell-low) → gamma unwind move amplify karta hai.

Expiry par far-OTM weekly options khareedna usually losing game kyun hai?

Savage theta decay + ITM finish hone ki low probability → negative expected value; writers systematically dusri side par hote hain.

Weekly aur monthly expiry effects mein kya difference hai?

Monthly mein bahut bada OI, rollovers, aur index rebalancing hoti hai → bade trends; weekly mein faster theta aur saste, high-turnover premiums hote hain.

Kya Max Pain guarantee hai?

Nahi — yeh ek probabilistic magnet hai jo tab mostly hold karta hai jab dealers strike ke paas net long gamma hon; news/bada flow/wall breaks ise override kar deta hai.

Open Interest (OI) kya hai?

Option contracts ki number jo currently open hain (abhi tak close ya expire nahi hue).

Connections

Options Greeks — Delta & Gamma
Theta Decay & Time Value
Open Interest & Volume Analysis
Delta Hedging by Market Makers
Gamma Exposure (GEX) & Dealer Positioning
Index Rebalancing Effects
When to Trade — Timing & Sessions
Implied Volatility & IV Crush