SENSEX expiry: 0DTE rush, 77,900 puts ₹0.05

Why this SENSEX expiry became a social-media talking point

Reddit and trading groups fixated on the SENSEX weekly expiry after posts claimed about ₹693 crore in 0DTE (same-day expiry) options traded. The attention centered on far out-of-the-money puts, especially the 77,900 PE, being marked at ₹0.05 in the shared option-chain snapshots. Traders highlighted how quickly option prices can compress to near-zero as time value collapses into the final hours. Multiple screenshots were circulated with timestamps around Aug 13, 2026, including a “market data refreshed” marker and a 15-minute delay note. Some posts also showed a SENSEX level around 78,707.09 at 00:38 (GMT-4), while another snapshot showed spot 77,746.63 at 04:01 am. The variation across images reinforced that these were point-in-time captures rather than a single consolidated feed. The tone of the discussion was less about direction and more about how expiry mechanics play out in the chain. It also triggered broader questions on lot size, cash settlement, and how to interpret OI spikes.

The numbers traders kept quoting from the option chain

A widely shared chain snapshot for Aug 13, 2026, 03:30 PM (15-min delay) showed Total Call OI at 3.03 Cr and Total Put OI at 2.93 Cr. The same snapshot labelled PCR as 0.97 and described it as neutral, with an approximate ATM strike near 78,100. Another set of posts showed a different roll-up with Call OI 3.21 Cr, Put OI 3.06 Cr, and PCR 0.95 alongside a spot reference of 77,746.63. Separate chatter also cited an OI refresh (13 Aug, 2026, 04:08 PM IST) where PCR was stated at 1.03. In that update, users said OI peaks were at 78,100 on the call side and 77,800 on the put side. Max pain was repeatedly referenced as 78,000 in the shared screenshots. A different excerpt mentioned “Total Open Interest 33,381,780” and a “PCR 0.71,” which shows that traders were pulling from different pages or time windows. The common thread was not a single “correct” number, but how rapidly these summaries can shift into expiry.

What “0DTE” meant in the SENSEX context

In the posts, 0DTE was used to describe SENSEX options that expire the same day, where theta decay dominates pricing. Because there is almost no time left, premiums can drop sharply if the index does not move toward the strike. That was the practical backdrop for why deep OTM puts were being discussed at ₹0.05. Traders were also sharing the standard explanation that an option gives the right, not the obligation, to benefit from a move in the index for a premium paid upfront. Social posts repeated that the maximum loss for an option buyer is limited to the premium paid. Many comments framed calls as positioning for an up-move and puts as positioning for a down-move or as a hedge. The expiry-day reality is that a large portion of strikes will become irrelevant if spot stays away from them. That can produce eye-catching last traded prices near the minimum tick value.

The 77,900 PE at ₹0.05 and what it signaled

The recurring claim was simple: 77,900 puts were seen settling or trading at ₹0.05 near the close on expiry day. Several rows in the shared chain table showed put LTPs at ₹0.05 across multiple strikes in the area, reinforcing the idea that these were far from being in-the-money at that moment. In the same snapshot style table, the 77,900 strike line was widely reposted, with both call-side activity and put-side LTP of ₹0.05 visible. Traders used it as a concrete example of how quickly expiry crush can reduce the premium on one side of the chain. Importantly, a ₹0.05 print does not, by itself, describe profitability for every participant because entry prices and timing differ. It also does not indicate the day’s total profit or loss for the market, only a last traded snapshot. What it did do was compress the discussion into an easy-to-understand visual: “deep OTM went to almost nothing.” For newer participants, this became a prompt to ask how cash settlement works and how final settlement value is determined.

PCR shifts: why different screenshots showed 0.71, 0.97, 1.03

The put-call ratio values discussed ranged from about 0.71 to 1.03 across various shared images. Users generally treated lower PCR readings as indicating relatively higher call positioning versus puts, but the posts also made clear the number was changing quickly. One snapshot listed PCR 0.97 with Total Call OI 3.03 Cr and Total Put OI 2.93 Cr near 03:30 PM. Another refresh showed PCR 1.03 with OI peaks at 78,100 calls and 77,800 puts at 04:08 PM IST. Elsewhere, a “Total Open Interest 33,381,780” panel showed a PCR of 0.71, suggesting a different aggregation or timestamp. These differences are typical when screenshots are taken at different moments or from different data providers. Social commentary also pointed out that OI is not the same as traded volume, and that expiry can cause both to jump due to rollovers and closing activity. The key takeaway from the chatter was to treat PCR as a live indicator, not a fixed verdict.

Cash settlement and expiry timing featured in the debate

Several posts repeated that SENSEX index options are cash settled in INR at expiry. That point came up because many retail traders still confuse index option settlement with the physical settlement used in some single-stock derivatives. The same explanations also stated that weekly contracts expire every Thursday, with monthly expiries on the corresponding week of the month. On expiry, the focus shifts from premiums to the final settlement value of the underlying index. Social threads also emphasized that an option buyer’s downside is limited to the premium, which matters most on 0DTE when positions can go to near-zero quickly. Another frequently repeated detail was that the option chain lists strike prices and expiry dates and displays real-time metrics like implied volatility, volume, and open interest. Traders used those fields to argue where “support” and “resistance” might be, based on OI build-up. The broader point was practical: expiry is about mechanics, not just market direction.

Lot size confusion: 10 units vs 20 units in shared posts

One reason the thread stayed active was that different screenshots described different lot sizes. Some posts said SENSEX options trade in lots of 20 units on BSE, while another snapshot showed “Lot Size 10 units” and “Lot 10” alongside a spot timestamp. Users also shared a generic explainer stating each SENSEX option contract “typically represents 10 units,” while other excerpts clearly said 20 units. Because these were social-media snippets, the disagreement was not resolved inside the thread. Traders repeatedly advised each other to check the current contract specifications on the exchange page before placing trades. The lot size directly affects premium outlay and risk, especially in 0DTE where small price changes can matter. This was also tied to the cash-settled nature of index options, where the contract multiplier influences settlement amounts. The discussion served as a reminder that “chain screenshots” are not a substitute for contract specs. For readers, the practical step is to verify lot size and tick size from the latest BSE product circulars or the official contract master.

Key levels and a quick table of the shared expiry metrics

Across the posts, the most referenced levels were the ~ATM strike near 78,100 and max pain around 78,000. OI concentration was discussed at 78,100 on calls and 77,800 on puts in one late-afternoon refresh. In the 03:30 PM delayed snapshot, Total Call OI and Total Put OI were shown as 3.03 Cr and 2.93 Cr, respectively, with PCR 0.97 marked as neutral. Another panel showed spot 77,746.63 and a different OI roll-up with PCR 0.95. The 77,900 PE at ₹0.05 remained the standout reference point for “expiry premium collapse.” These numbers were treated as signposts rather than predictions, since they were captured at specific times. Below is a consolidated table of what was explicitly shared in the screenshots, without reconciling discrepancies.

What traders can realistically take away from the chatter

The strongest lesson from the thread is that expiry-day option prices can become extreme, including prints at ₹0.05 for far OTM strikes. The second lesson is that aggregated indicators like PCR can differ across screenshots, even on the same day, because data updates and time windows vary. Third, OI peaks and max pain levels are descriptive of positioning shown in the chain, not guarantees of where the index will settle. Fourth, contract details matter more on expiry, and the lot size confusion in the posts shows why traders should verify specs from the exchange. Fifth, cash settlement removes delivery risk but does not remove trading risk, especially when premiums decay quickly. Finally, the social-media focus on a single strike like 77,900 PE is useful as an example, but it should not replace a full view of strikes around spot and the chosen expiry. For anyone new to 0DTE, the most practical approach is to treat option-chain screenshots as context and double-check live exchange data before acting. That is also the simplest way to avoid misreading a rapidly changing expiry tape.