25 lines
999 B
YAML
25 lines
999 B
YAML
id: CONV-001
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title: Historical GLD Backing Lookup
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status: backlog
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priority: P1
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size: S
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depends_on:
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- PRICING-001
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tags: [conversion, historical]
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summary: Support lookups of GLD ounces-per-share for historical dates.
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acceptance_criteria:
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- `gld_ounces_per_share(entry_date)` returns accurate backing for any date
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- Formula validates against known points (launch 2004, current 2026)
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- Conversion between GLD shares and gold oz uses entry_date backing
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- Error handling for dates outside GLD lifetime (pre-2004)
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- Cache-friendly for repeated lookups
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notes:
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- GLD launched Nov 2004 with 0.10 oz/share
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- Current backing ~0.0916 oz/share (2026)
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- Formula: `0.10 × e^(-0.004 × years_since_2004)`
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- Future enhancement: fetch actual NAV/ounce from spdrgoldshares.com
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implementation_hints:
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- Already implemented for current date in `app/domain/instruments.py`
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- Extend to accept `date` parameter
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- Clamp dates to GLD lifetime (Nov 2004 to present)
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- Add historical validation tests |