<h1>Put-call ratio (PCR) as options-market sentiment gauge, its calculation, limits, and use alongside other risk metrics</h1> No statutory, regulatory, or contractual instrument is reported; the text does not introduce any legal change, clarification, prohibition, permission, or compliance requirement. It describes the put-call ratio (PCR) as an options-market sentiment indicator, explains its calculation using volume or open interest, and notes interpretive conventions for PCR levels and extremes, including stated limitations (e.g., inability to distinguish hedging from speculation and distortions around expiry or events). The operative consequence is informational only: it suggests how market participants may use PCR alongside other market metrics to assess positioning and risk in increasingly derivatives-driven trading, without creating enforceable rights, duties, or liabilities.