# State 008 Fidelity Profile

> For the complete documentation index, see [llms.txt](https://deploy-preview-472--lucky-concha-f3599f.netlify.app/llms.txt).

This profile captures the required technical shape for state `008-pricing-awareness-market-data`.

## Runtime Stack Deltas From State 007

| Concern | State 007 | State 008 |
| --- | --- | --- |
| Messaging backbone | `nats-broker` | `nats-broker` + `price-publisher` |
| Trade schema | quantity/state only | \+ execution `price` |
| Position schema | quantity only | \+ `averageCostBasis` |
| Browser real-time stream | account-scoped trade/position updates | account-scoped updates + `pricing.*` streams |
| Runtime model | Docker Compose | Docker Compose |

## Pricing Constraints

*   Persisted `price` and `averageCostBasis` use 3-decimal precision.
*   Market data tick generation is synthetic random walk bounded by startup open/close with per-ticker startup-assigned band profile:
    *   20% of tickers: up to ±4% beyond open/close,
    *   60% of tickers: up to ±2% beyond open/close,
    *   20% of tickers: strict open/close bounds.
*   Bootstrap mode:
    *   `snapshot` for deterministic local behavior,
    *   `yfinance` for startup seeding from recent market data.
*   Publish model:
    *   randomized interval defaults to `750-1500ms`,
    *   each cycle publishes a randomized subset (default `25%`) of symbols,
    *   all parameters are runtime-configurable.
*   Symbol universe:
    *   reference-data and price-publisher are configured to share the same supported symbol list,
    *   legacy `FB` is normalized to `META` in reference-data outputs.

## UI Fidelity Constraints

*   Position blotter includes `OPEN`, `MKT PRICE`, `POSITION VALUE`, and `P&L`.
*   Market price row semantics are computed against open price:
    *   above open: `▲` + green highlight,
    *   below open: `▼` + pink highlight,
    *   equal open: neutral marker.
*   Position value and P&L use green/pink highlight semantics for positive/negative valuation state.

## Closeness Policy

State `008` is functional-close to `007` with additive pricing behavior.  
Messaging/runtime architecture remains unchanged except for adding the pricing publisher component.