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Epic 2: Returns Method Configuration

Status: ✅ Complete (January 2026)

Overview​

Administrators can now toggle the return calculation method for each entity between:

  • Modified Dietz: daily_pnl / prior_day_nav (matches BTIG)
  • Simple Flat Capital: daily_pnl / month_start_capital (original AIC method)

Database Schema​

Entity Table Addition​

-- Migration: 20260114212305_add_return_method_to_entity.sql

ALTER TABLE sable.entity
ADD COLUMN IF NOT EXISTS return_method TEXT
DEFAULT 'modified_dietz'
CHECK (return_method IN ('modified_dietz', 'simple_flat'));

Column Details:

  • Default: modified_dietz (for BTIG reconciliation accuracy)
  • Constraint: Only allows the two valid method values
  • All existing entities default to Modified Dietz

View Update​

The gold.v_dietz_daily view respects the entity's return_method setting:

-- Migration: 20260114212344_update_v_dietz_daily_for_method_toggle.sql

-- Return calculation switches based on method
CASE return_method
  WHEN 'modified_dietz' THEN daily_pnl / begin_nav
  WHEN 'simple_flat' THEN
    CASE WHEN capital_amount > 0
      THEN daily_pnl / capital_amount
      ELSE NULL
    END
  ELSE daily_pnl / begin_nav  -- Default fallback
END AS daily_return

The view exposes return_method column for transparency.

Admin UI​

Location​

Settings page: /protected/settings

Component​

EntityReturnMethodsCard (components/settings/entity-return-methods-card.tsx)

Features​

  • Lists all entities for the organization
  • Dropdown to select calculation method
  • Real-time save with visual feedback
  • Explanatory descriptions for each method

Screenshot​

┌─────────────────────────────────────────────────────────┐
│ 📊 Return Calculation Methods                           │
│ Configure how daily returns are calculated per entity   │
├─────────────────────────────────────────────────────────┤
│                                                         │
│ Anthracite Holdings LP                                  │
│ Daily PnL / Prior Day NAV (matches BTIG)               │
│                                    [Modified Dietz ▼]   │
│                                                         │
│ Anthracite Realty Partners, LLC                        │
│ Daily PnL / Prior Day NAV (matches BTIG)               │
│                                    [Modified Dietz ▼]   │
│                                                         │
│ Bird Family Foundation                                  │
│ Daily PnL / Prior Day NAV (matches BTIG)               │
│                                    [Modified Dietz ▼]   │
│                                                         │
├─────────────────────────────────────────────────────────┤
│ Method Descriptions:                                    │
│ • Modified Dietz: Daily PnL / prior day NAV. Matches   │
│   BTIG calculation for reconciliation accuracy.         │
│ • Simple Flat Capital: Daily PnL / month-start capital │
│   This is the original AIC calculation method.          │
└─────────────────────────────────────────────────────────┘

Method Comparison​

AspectModified DietzSimple Flat Capital
Formuladaily_pnl / begin_navdaily_pnl / capital_amount
DenominatorPrior day's NAVMonth-start capital
Cash flow handlingTime-weightedDeferred
BTIG match✅ Yes❌ No
Use caseReconciliationLegacy reporting

When to Use Each Method​

  • Default for all entities
  • Use for BTIG reconciliation
  • More accurate for entities with frequent cash flows
  • Industry standard for time-weighted returns

Simple Flat Capital​

  • Legacy AIC calculation method
  • Use only if explicitly required for specific reporting
  • Not recommended for entities with cash flows

Implementation Files​

FilePurpose
supabase/migrations/20260114212305_*.sqlAdd return_method column
supabase/migrations/20260114212344_*.sqlUpdate v_dietz_daily view
components/settings/entity-return-methods-card.tsxAdmin UI component
app/protected/settings/page.tsxSettings page integration