{"id":6887,"date":"2026-09-09T09:50:33","date_gmt":"2026-09-09T09:50:33","guid":{"rendered":"https:\/\/eodhd.com\/financial-academy\/?p=6887"},"modified":"2026-09-09T09:50:33","modified_gmt":"2026-09-09T09:50:33","slug":"anatomy-of-one-option-greeks-over-time","status":"publish","type":"post","link":"https:\/\/eodhd.com\/financial-academy\/stock-options\/anatomy-of-one-option-greeks-over-time","title":{"rendered":"Anatomy of One Option: The Full Life of a Contract in 43 Fields"},"content":{"rendered":"\n

Every options tutorial has the same diagram: a smooth curve showing time decay, drawn from a formula. It’s correct and it teaches you almost nothing, because the interesting part isn’t the shape of the curve \u2014 it’s what the numbers actually do to a real contract that real people were trading.<\/p>\n\n\n\n

So let’s take two of them and watch their entire lives, field by field.<\/p>\n\n\n\n

Both are Apple calls expiring on 19 December 2025. One was struck at 250, the other at 270. Over the last 90 days of their lives Apple rose 11%, from 244.60 to 271.45. The 250 call more than doubled. The 270 call lost a fifth of its value<\/strong>. Same underlying, same expiry, the stock going the way both needed it to \u2014 opposite outcomes, and the reason is visible in the data day by day. Every option price below is the midpoint of the closing bid and ask \u2014 a mark, not an execution, and I’ll come back to what that costs.<\/p>\n\n\n\n

Where the data comes from.<\/strong> Everything here is built on the EODHD US Stock Options Data API<\/a>, which serves one daily record per listed US equity option contract: volume, open interest and their daily changes, bid and ask with sizes, implied volatility and its change, all five Greeks, days to expiry and moneyness. A contract’s entire history comes back in a single request. The API documentation<\/a> has the full field list.<\/p>\n\n\n\n

You can run every line below without an account: EODHD publishes a demo<\/strong> token that answers for AAPL and AMZN, and that’s the token in the code.<\/p>\n\n\n\n

<\/div>\n\n\n\n

Two contracts, two requests<\/h2>\n\n\n\n

Option contract symbols are mechanical once you’ve seen one: the underlying, the expiry as YYMMDD, C or P, then the strike times a thousand padded to eight digits. So the 250 call expiring 19 December 2025 is AAPL251219C00250000.<\/p>\n\n\n\n

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import requests\n\n# EODHD US Stock Options Data API\n# docs: https:\/\/eodhd.com\/marketplace\/unicornbay\/options\/docs\nBASE = \"https:\/\/eodhd.com\/api\/mp\/unicornbay\/options\"\nTOKEN = \"demo\"          # EODHD's public demo token: AAPL and AMZN, no signup\n\nFIELDS = (\"contract,tradetime,exp_date,dte,strike,type,volume,open_interest,\"\n          \"open_interest_change,bid,ask,volatility,volatility_change,\"\n          \"delta,gamma,theta,vega,rho,moneyness\")\n\ndef contract_life(symbol):\n    \"\"\"Every session this contract ever traded, oldest first.\"\"\"\n    r = requests.get(f\"{BASE}\/eod\", params={\n        \"filter[contract]\": symbol,\n        \"fields[options-eod]\": FIELDS,\n        \"page[limit]\": 1000, \"api_token\": TOKEN,\n    })\n    rows = 
<\/div> for row in r.json().get(\"data\", [])]\n    rows = [x for x in rows if x.get(\"tradetime\")]\n    return sorted(rows, key=lambda x: x[\"tradetime\"])\n\nitm = contract_life(\"AAPL251219C00250000\")   # ended deep in the money\natm = contract_life(\"AAPL251219C00270000\")   # ended near the money\n\nprint(len(itm), \"sessions:\", itm[0][\"tradetime\"], \"\u2192\", itm[-1][\"tradetime\"])<\/code><\/pre>\n\n                <\/div>\n                
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