The prices displayed on the chart for illiquid options may not always reflect their fair value at closing. This is because, unlike options where the settlement price is calculated as the weighted average over the last 30 minutes of trading for the day, illiquid options see less frequent trading activity and hence will not have enough trades (Or no trades at all) for calculating the weighted average in the last 30 minutes.

So to provide users with a better understanding of closing prices for illiquid options, we rely on settlement price values provided by the exchange in the “Bhav Copy” instead of the last traded price(LTP) which is reflected in the charts. Here is some data that offers a more accurate representation of their closing value since it is calculated as per the formula prescribed by the exchange.

Therefore, you may observe discrepancies between the chart and positions tab prices for illiquid option strikes.