Reference · Cheat sheet

The Four Wishes

Every single-leg option position is one of four wishes about price. Two words decide it.

Call (about upside)Put (about downside)
Long (bought)Up. Wants spot above strike. Pays premium. Loss capped at premium.Down. Wants spot below strike. Pays premium. Loss capped at premium.
Short (sold)Not up. Wants spot at or below strike. Receives premium. Loss open-ended.Not down. Wants spot at or above strike. Receives premium. Loss large (to zero).

The test that never fails

When does my option become worthless, and do I want that?

A ₹2,600 call is worthless if Reliance ends at or below ₹2,600. If you bought it, that's your nightmare, so you want above. If you sold it, that's your payday, so you want at-or-below.

The same table in Varsity's words

ViewPositionPremium
BullishLong callPay
Flat or bullishShort putReceive
Flat or bearishShort callReceive
BearishLong putPay

Source: Zerodha Varsity, Summarizing Call & Put Options. Note that "flat" appears only in the short rows: sellers are paid for stillness.

Worked numbers, Reliance at ₹2,500, lot 250

At expiryLong 2,600 call, paid 30Short 2,600 call, got 30Long 2,400 put, paid 28Short 2,400 put, got 28
₹2,200−30+30+172−172
₹2,400−30+30−28+28
₹2,500−30+30−28+28
₹2,600−30+30−28+28
₹2,800+170−170−28+28

Per share. Multiply by 250 for the lot. Each short column is its long column with the sign flipped: same contract, other side.