Historical PCR Analysis: Read Multi-day Trends

What the multi-day workspace adds

The workspace plots available observations across the chosen date window. OI PCR and volume PCR describe different option-chain totals; Premium WPCR and Delta-OI WPCR use different weights. Underlying price is kept as context, with its own scale. The selected window is a request for available history, not a guarantee that every date has data.

Use the session PCR chart when the question concerns one day at a fixed intraday interval. Use multi-day analysis when you need to compare recent levels, see persistence or check whether an apparent extreme is unusual within the available sample.

Screenshot: the history window and metrics

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1. Expiry and end date. Keep the contract and historical end date comparable across windows.
2. History window. The 5, 10 and 30 day controls request available history; they do not guarantee a complete daily sample.
3. Current readings. Standard OI and volume ratios differ from premium and delta-weighted measures.
4. Metric labels. Use the legend and both scales to distinguish price from each ratio.

Historical PCR tool workspace with numbered controls and reading points

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Set up a comparable historical view

1. Open the instrument page and its filters. Select the underlying and expiry before the date window.
2. Choose 5 Days, 10 Days or 30 Days. If using a historical end date, verify that the expiry and available series resolve for that date.
3. Start with OI PCR and price. Add volume PCR, then one weighted measure so each comparison has a clear purpose.
4. Switch to the data table to inspect the observation date and value behind a line segment. Missing dates should remain missing rather than being read as zero.
5. Repeat with another window while keeping expiry and metric fixed. A different scale or number of observations can change the apparent shape.

Worked example: a changing denominator

Suppose put OI is 12 million and call OI is 10 million: OI PCR is 1.20. On the next observation put OI is still 12 million while call OI falls to 8 million: PCR becomes 1.50. The increase did not require any new put OI. Inspect the chain totals before assigning a cause to a rising ratio.

These are illustrative figures. If the selected expiry changes between the observations, the comparison also changes the contract group; that is different from a continuous change within one expiry.

History and measurement limits

A high reading relative to the visible window is not a calibrated probability of reversal. Different expiries, strike coverage, missing deltas and small call-side denominators can alter comparisons. A historical chart is descriptive and does not identify who initiated the trades.

Use the weighted PCR guide for the weighting formulas and the session walkthrough for one-day chart controls.