The defined-risk alternative

At the 8 Oct 2026 closes (bhavcopy; lot 225): 2080 call 57.75, 2080 put 60.75, 2180 call 24.75, 1980 put 22.75. At the 9 Oct closes: 102.70, 17.65, 40.35 and 6.30. (a) For the short iron butterfly (sell the 2080 call and put, buy the 2180 call and 1980 put), compute the net credit per share, the maximum loss per lot and the two break-evens at expiry. (b) How many lots does the 1% rule allow for the butterfly, and for a long ATM straddle sized by its premium? (c) Compute the butterfly's gross P&L per lot from the 8 Oct close to the 9 Oct close. (d) TCS settled at ₹2,496.90 on 27 Oct. What would the butterfly have been worth at expiry, per share? Why is the long straddle's expiry profit of ₹67,140 per lot not evidence for a "buy straddles before results and hold" rule?