# Fixed-Point and Minute-Stream Acceptance

Acceptance date: 2026-08-31  
Engine commit: `cd116bc3ae77cac0989eb80185bb04d7440b8834`

## Scope

This acceptance separates execution precision from minute-data throughput. It
does not use a strategy-specific shortcut and does not change strategy,
matching, risk, slippage, commission, tax, or future-data semantics.

## Fixed-Point Boundary

- Execution money is signed micro-yuan `i128`.
- Stock gross amount, commission, stamp tax, transfer fee, cash, liabilities,
  external cash flow, account units, position lot cost and PnL are fixed-point.
- Futures cash, margin, transaction cost, realized PnL and position PnL are
  fixed-point.
- Market indicators and return statistics remain `f64`; conversion occurs only
  at the execution-money boundary.
- One-micro-yuan budget overruns fail instead of being hidden by float epsilon.

Verification command:

```bash
cargo test -p fidc-core fixed -- --nocapture
```

Result: 8 passed, 0 failed.

## Minute Data Boundary

- `history_intraday_quotes_at` uses a sorted execution-date index and scans
  backward until the requested bar count is satisfied.
- The active timestamp and `include_now` flag control visibility; later bars are
  never visible.
- Daily minute execution consumes a borrowed k-way merge ordered by timestamp
  and symbol. It does not clone the complete selected quote day before engine
  dispatch.
- Execution quotes are released by trading date after the day finishes.

Release benchmark command:

```bash
cargo test -p fidc-core --test intraday_history_performance --release -- --ignored --nocapture
```

Observed on the local acceptance host:

| Case | Workload | Result |
| --- | --- | --- |
| Bounded history | 200 queries over 60,000 rows | 0.000227 seconds, checksum 351450348000 |
| Full-day materialization | 5,000 iterations x 240 rows | 0.049361 seconds |
| Borrowed quote stream | 5,000 iterations x 240 rows | 0.012232 seconds |

The materialized and streamed timestamp checksums were both
`2108693484000000`. The observed component speedup was about 4.04x. These
numbers are component evidence only and are not an end-to-end SLA.

## Regression

```bash
cargo test -p fidc-core --all-targets
```

Result: 528 passed, 0 failed, 1 ignored manual benchmark. This includes
execution-day risk, next-open open-price limits, minute timestamp visibility,
slippage, minimum commission, stamp tax, volume limits, corporate actions,
external cash-flow NAV treatment and futures account precision.

## Deployment Gate

This documentation-only correction does not require a service restart. Any
future Source Lake or engine deployment still requires the official managed
entrypoint and must fail closed while FIDC-managed factor work is active.