How to compute net Delta, Gamma, Theta, and Vega for any combination of options. The skill that separates serious traders from premium guessers.
Every multi-leg option position has net Greeks that are just the sum of the individual leg Greeks, weighted by contracts per leg. Net Delta tells you your directional exposure. Net Gamma tells you how that exposure shifts as the market moves. Net Theta tells you your daily decay. Net Vega tells you your IV exposure.
Reading net Greeks is the difference between trading multi-leg positions blind and trading them with full risk awareness. Every position type has a recognisable Greeks signature — once you can read it, the strategy stops being a name and becomes a risk profile.
Buy ATM call + buy ATM put. Net Delta ≈ 0 (calls +0.50 + puts -0.50). Net Gamma is high and positive (both legs are long Gamma). Net Theta is very negative (paying two premiums). Net Vega is high and positive (both legs are long Vega).
Reading the profile: directional-neutral at entry, profits if the underlying moves in EITHER direction enough to overcome combined premium, bleeds Theta every day, benefits from IV expansion. Classic pre-event trade.
Sell OTM call (say 1% above spot) + sell OTM put (say 1% below spot). Net Delta ≈ 0. Net Gamma is negative (you're short two long-Gamma options). Net Theta is high and positive (you're collecting two premiums of decay). Net Vega is negative (IV expansion hurts you).
Reading the profile: directional-neutral if the underlying stays in range, profits from time decay and IV crush, but unlimited loss if either side breaks out. Most popular Indian income strategy on weekly options.
Sell OTM call + buy further-OTM call (call credit spread) + sell OTM put + buy further-OTM put (put credit spread). Like a short strangle but with the tails protected by longer-strike longs.
Net Delta ≈ 0. Net Gamma is slightly negative. Net Theta is positive (smaller than short strangle because you're paying for the wing protection). Net Vega is slightly negative.
Reading the profile: same upside as short strangle but with defined max loss = spread width minus credit collected. Lower reward, much lower risk. Most disciplined version of income selling.
Sell near-dated option + buy same-strike longer-dated option. Net Theta is positive (near-dated decays faster than longer-dated). Net Vega is positive (longer-dated has more Vega than near-dated). Net Delta is slightly positive or negative depending on strike vs spot.
Reading the profile: profits when the underlying stays near the strike (Theta differential maximised at ATM) AND when IV rises (Vega positive). Best in sideways, low-IV markets ahead of a known catalyst.
Net Delta = 2 × (+0.40) + 1 × (-0.30) = 0.80 - 0.30 = 0.50. The position is moderately bullish — every 100-point NIFTY rise produces +0.50 × 25 × 100 = ₹1,250 of P&L change (before Gamma adjusts the Delta).
Strangle = sell OTM call + sell OTM put (2 legs). Iron condor = same but ADD long calls and long puts even further OTM as wings (4 legs). The wings cap max loss but reduce premium collected. Iron condor is 'strangle with seatbelts'.
When you expect IV to rise AND the underlying to stay near a specific strike. The calendar harvests Theta differential and benefits from Vega expansion. Straight long options bleed Theta on quiet days; calendars don't.
Three reasons: (1) spot moves change Delta via Gamma, (2) IV moves change Vega via Vomma, (3) time passing changes everything via Theta. Greeks are dynamic — they're snapshots of current risk, not fixed properties of your position.
Better: use net P&L at adverse-scenario prices. Set the stop on dollar loss, not Greek values. Greeks predict P&L change but the actual loss includes path-dependent effects too.