WST Open Interest
West Pharmaceutical Services Inc (WST) had 6.4K open option contracts as of Nov 4, 2026: 3.65K calls and 2.75K puts. Open interest rose 27.3% over the past four weeks, and is WST's highest level in 4 weeks. The put/call open interest ratio is 0.75, so calls outnumber puts.
Open Interest by Strike
Showing results for WST, 2026-11-20(m), calls & puts
Open Interest Stats
Showing results for WST, 2026-11-20(m), calls & puts
| Call Open Interest Total | |
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| Put Open Interest Total | |
| Open Interest Total | |
| Put-Call Open Interest Ratio |
Highest Open Interest Options
Showing results for WST, 2026-11-20(m), calls & puts
Open Interest Total by Expiry
Showing results for WST, 2026-11-20(m), calls & puts. View all expiries
Open Interest History
Showing daily totals for WST, all expirations, calls & puts. View full history
WST Open Interest FAQ
What is open interest?
Open interest is the number of option contracts that are open and not yet closed, exercised, or expired. The Options Clearing Corporation calculates it once a day from the previous day's trades, and it is published before the market opens.
How much open interest does WST have?
West Pharmaceutical Services had 6.4K open option contracts as of Nov 4, 2026. Over the past 30 days, open interest averaged 5.27K contracts.
Is WST open interest rising or falling?
Open interest rose 27.3% over the past four weeks, and is WST's highest level in 4 weeks. It was 5.02K contracts on Oct 7, 2026. See the WST open interest history for a longer view.
What is the WST put/call open interest ratio?
The West Pharmaceutical Services put/call open interest ratio was 0.75 as of Nov 4, 2026. Four weeks earlier it was 0.73.
What is West Pharmaceutical Services Inc?
West Pharmaceutical Services is based in Pennsylvania and is a key supplier to firms in the pharmaceutical, biotechnology, and generic drug industries.