{
 "site": "options.wiki",
 "section": "Contract conventions",
 "url": "https://options.wiki/conventions/",
 "reviewed": "2026-08-26",
 "license": "CC BY 4.0",
 "changes": "https://options.wiki/changes.json",
 "tables": [
  {
   "title": "Standard listed equity option",
   "columns": [
    "Attribute",
    "Convention"
   ],
   "rows": [
    [
     "Multiplier",
     "100 shares per contract unless the contract has been adjusted"
    ],
    [
     "Quotation",
     "Price per share. A quote of 2.50 costs 250.00 for one standard contract"
    ],
    [
     "Exercise style",
     "American"
    ],
    [
     "Settlement",
     "Physical delivery"
    ],
    [
     "Standard expiration",
     "The third Friday of the expiration month"
    ],
    [
     "Trading hours",
     "9:30 to 16:00 Eastern for most equity options"
    ],
    [
     "Minimum increment",
     "Commonly 0.01 for series under 3.00 and 0.05 above, varying by penny-quoting program membership"
    ]
   ]
  },
  {
   "title": "OSI option symbol structure",
   "intro": "The 21-character Options Symbology Initiative format. Reading the strike field wrong by a factor of 1000 is the most common parsing bug.",
   "columns": [
    "Field",
    "Width",
    "Format",
    "Example"
   ],
   "rows": [
    [
     "Root symbol",
     "6",
     "Left-justified, space-padded",
     "AAPL"
    ],
    [
     "Expiration",
     "6",
     "YYMMDD",
     "260918"
    ],
    [
     "Type",
     "1",
     "C or P",
     "C"
    ],
    [
     "Strike",
     "8",
     "5 digits whole, 3 digits decimal, zero-padded, no decimal point",
     "00185000 = strike 185.00"
    ]
   ]
  },
  {
   "title": "Expiration cycles",
   "columns": [
    "Type",
    "Schedule",
    "Note"
   ],
   "rows": [
    [
     "Monthly",
     "Third Friday of the month",
     "The historical standard. Deepest liquidity in most names"
    ],
    [
     "Weekly",
     "Most Fridays that are not a third Friday",
     "Now listed on a wide set of underlyings"
    ],
    [
     "Quarterly",
     "Last business day of a calendar quarter",
     "Primarily index and ETF products"
    ],
    [
     "LEAPS",
     "Long-dated, generally more than nine months to expiration, expiring on a January third Friday",
     "Marginable differently from short-dated options"
    ],
    [
     "Daily",
     "Every trading day on selected high-volume index products",
     "Concentrated in the largest index and ETF underlyings"
    ]
   ]
  }
 ],
 "entries": [
  {
   "id": "expiration-date-history",
   "term": "Expiration date - Friday, not Saturday",
   "definition": "Standard monthly listed options expire on the third Friday of the expiration month. Prior to a rule change effective with February 2015 expirations, the technical expiration date was the Saturday following the third Friday, with Friday as the last trading day.",
   "notes": [
    "Historical data sets and older documentation may carry Saturday expiration dates. Date-matching against a modern calendar will fail on those rows.",
    "When the third Friday is an exchange holiday, expiration moves to the preceding Thursday."
   ],
   "sameAs": [
    "https://www.wikidata.org/wiki/Q2501440",
    "https://en.wikipedia.org/wiki/Expiration_(options)"
   ],
   "citations": [
    {
     "name": "SEC order approving SR-OCC-2013-04 (Friday expiration)",
     "url": "https://www.sec.gov/files/rules/sro/occ/2013/34-69772.pdf"
    }
   ]
  },
  {
   "id": "moneyness",
   "term": "Moneyness",
   "definition": "The relationship between the underlying price and the strike, stated from the perspective of the long holder.",
   "fields": [
    {
     "label": "Call in the money",
     "value": "S > K",
     "mono": true
    },
    {
     "label": "Call out of the money",
     "value": "S < K",
     "mono": true
    },
    {
     "label": "Put in the money",
     "value": "S < K",
     "mono": true
    },
    {
     "label": "Put out of the money",
     "value": "S > K",
     "mono": true
    },
    {
     "label": "Intrinsic value (call)",
     "value": "max(S - K, 0)",
     "mono": true
    },
    {
     "label": "Intrinsic value (put)",
     "value": "max(K - S, 0)",
     "mono": true
    },
    {
     "label": "Extrinsic value",
     "value": "Option price - intrinsic value",
     "mono": true
    }
   ],
   "notes": [
    "Extrinsic value is always non-negative for a fairly priced option and decays to zero at expiration.",
    "Delta is frequently used as a rough proxy for the probability of finishing in the money. It is a biased proxy, not an identity - it equals the risk-neutral probability only for d2, not d1."
   ],
   "sameAs": [
    "https://www.wikidata.org/wiki/Q1806850",
    "https://en.wikipedia.org/wiki/Moneyness"
   ],
   "citations": []
  }
 ]
}