S2Ep113 | One Stock, Two Exchanges, Two Prices | IndusInd Closes 1002.90 And 970 On The Same Day | BANKEX -1,094 Points vs Nifty Bank -0.47%, Nine Of Ten Worst Dislocations Are Banks | Sensex Indicative Flashes 75098, Monthly Settles 667 Points Below

IndusInd Bank closed at 1,002.90 on one exchange and 970 on the other. Same stock, same second, 3.3% apart. Federal Bank: 344.80 against 334.10. IDFC First: 83.80 against 81.30. PNB: 115.40 against 112. Episode 113 examines what the closing auction did to the Indian cash market on Sensex monthly expiry day, using the official BhavCopy from both exchanges.What happened: through Thursday afternoon the Sensex traded between 77,200 and 77,300. At 15:22 the indicative close flashed 75,098.23, roughly 2,200 points below the tape. The final settlement printed 76,933.59, which was also the low of the day, making it the third consecutive session where the close was the low and was set after continuous trading ended. Around 370 points of the 539-point fall arrived after the tape stopped. The August Sensex contracts settled at 76,933.59, which is 667 points BELOW the 77,600 max pain flagged that morning.The result in the indices: the BANKEX fell 1,094.16 points, 1.67%, while the Nifty Bank fell 0.47%. Two bank indices holding largely the same banks, on the same day, 1.2 percentage points apart. The Nifty closed 24,090.85, also its low.The forensic, and the honest version: every liquid stock trading on both exchanges was compared, 1,197 names. The median difference between the two closing prices was 0.00%. For the deep, liquid part of the market the auction worked exactly as designed. 53 stocks, 4.2% of the sample, closed more than 1% apart. So this was not a market-wide failure.But the tail is a sector, not a scatter. The ten worst dislocations: IndusInd -3.28%, Federal -3.10%, IDFC First -2.98%, PNB -2.95%, Union Bank -2.49%, Canara -2.41%, Yes Bank -2.29%, Bank of Baroda -1.85%, AU Small Finance -1.83%. Nine of ten are banks. On the Sensex 30, seven of thirty closed more than half a percent apart, and ETERNAL closed UP 0.46% on one exchange and DOWN 0.92% on the other: opposite directions for the same company.The mechanism, in plain language: a closing auction makes the close harder to push around, and where books are deep it does that well. But an auction needs depth. Where the book is thin in that window, one imbalance sets the print and there is no continuous market left to argue with it. Every index level, fund NAV, margin call and derivative settlement is computed off those prints.The board: calls were written 3.5x faster than puts for a third straight session (582 lakh vs 166 lakh), 24300 is now the biggest position at 132.5 lakh, puts were pulled off 24350 and 24300 while fresh puts were built at 24000 (now 70.4 lakh) and 23800. PCR has collapsed three sessions running, 1.159 to 0.733 to 0.593. Gamma flips positive at 24300 with spot 210 points below it.The participants: proprietary desks are net short calls for the first time this cycle. Retail bought 98,000 more calls AND added 98,000 more naked puts, taking that book to 7.61 lakh, a third straight session adding both legs into a falling market. Domestic institutions wrote another 4,977 crore cheque.Data sourced from NSE, BSE, SEBI, NSDL and CDSL. New episode every trading day at 8:30 AM IST. The Tanmay Edge streams first on rupeecase.com. Educational content, not investment advice. SEBI RA application under process.