# Weighted Average Cost MVP Method

This project uses Weighted Average Cost (WAC) as the MVP internal portfolio performance method.

## Scope

- Buys increase quantity and cost basis.
- Buy fees increase cost basis.
- Partial sells reduce quantity and cost basis proportionally.
- Realized P&L is calculated against average cost at the time of sale.
- Full sells set quantity and remaining cost basis to zero.
- Dividends and ETF distributions increase income, but do not change quantity or cost basis.

## Non-goals

WAC in this system is not a complete tax method and is not tax advice.

The MVP intentionally does not implement:

- FIFO
- LIFO
- Swiss tax-lot reconstruction
- broker-specific tax reporting

The transaction ledger stays granular so tax-lot logic can be added later without replacing the accounting foundation.