State 007 Fidelity Profile

This profile captures the required technical shape for state 007-pricing-awareness-market-data.

Runtime Stack Deltas From State 006

Concern	State 006	State 007
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 007 is functional-close to 006 with additive pricing behavior.
Messaging/runtime architecture remains unchanged except for adding the pricing publisher component.