jgrusewski 3e9cefdbd9 fix(sp18-v2): restore-best precedes shrink-and-perturb at fold transition
`train_walk_forward` called `reset_for_fold().await?` directly at the
fold boundary, which applies `shrink_and_perturb(α=0.8, σ=0.01)` to
whatever `params_flat` holds. At end-of-fold, `params_flat` carries the
LATEST-EPOCH decayed weights, NOT the best-Sharpe snapshot saved
mid-fold. Fold N+1 then started from `0.8 × decayed + noise` and
carried the within-fold edge-decay forward.

Insert `restore_best_gpu_params()` BEFORE `reset_for_fold` so S&P
operates on the best-Sharpe snapshot. Cold-start guard swallows the
"no snapshot saved" error on the first fold (or any fold without a
Sharpe improvement) — matches pre-fix behavior on cold start, no
regression.

State interaction with `reset_for_fold`: restore-best writes
`params_flat` ONLY (online weights); reset_for_fold then runs S&P on
the restored online, hard-syncs target ← restored online, and resets
Adam state on every optimizer. Non-conflicting.

`best_params_snapshot` is constructor-init `None` on FusedTrainingCtx
and is NEVER cleared at fold boundary. The trainer's `self.best_sharpe`
IS reset to NEG_INFINITY in `reset_for_fold` so the first improvement
in fold N+1 will overwrite the snapshot. Until then, the snapshot holds
whichever fold most recently saved a peak — intended training-scoped
behavior. Strict within-fold semantics flagged as a follow-up
consideration.

Behavioral test (CPU oracle) pins the math contract:
  - shrink_and_perturb(α, σ) on X = α × X + (1−α) × N(0, σ)
  - with-fix vs without-fix differ by α × (W_best − W_curr)
  - cold-start (best == current) is bit-identical between orderings

GPU-level kernel coverage stays in compile_training_kernels smoke and
the L40S 30-epoch validation gating SP18 Phase 1.

Pre-commit Invariant 7: docs/dqn-wire-up-audit.md updated with full
rationale, state-interaction analysis, lifecycle notes, and the
preserved cross-pearl invariants.

Per:
- feedback_no_partial_refactor (call-ordering + test + audit-doc atomic)
- feedback_no_legacy_aliases (reuses existing API unchanged)
- feedback_wire_everything_up (restore_best_gpu_params gains second
  cold-path consumer)
- pearl_no_host_branches_in_captured_graph (runs outside graph capture)
2026-05-09 01:36:52 +02:00

Foxhunt

Production HFT trading system in Rust.

Architecture

The workspace contains 32 crates organized as follows:

Core Libraries (16)

Crate Purpose
trading_engine Order processing, FIX 4.4, IB TWS, SIMD, RDTSC timing
risk VaR, Kelly, circuit breakers, kill switches, compliance
risk-data Risk data types and shared structures
trading-data Trading data types
ml DQN Rainbow, PPO, TFT, Mamba2, ensemble inference
ml-data ML data types and feature definitions
data Market data ingestion and storage
backtesting Replay engine, strategy tester
adaptive-strategy Ensemble execution, microstructure analysis
common Shared types, resilience, error handling
storage S3 and local model storage
model_loader Model serialization and loading
market-data Market data feed handlers
database PostgreSQL access layer (SQLx)
config Configuration management
tli CLI commands and tooling

Services (8)

Service Purpose
backtesting_service gRPC backtesting service
broker_gateway_service FIX routing, broker connectivity
trading_service Core trading operations
ml_training_service Model training orchestration
data_acquisition_service Market data acquisition
trading_agent_service Autonomous trading agents
api_gateway gRPC API gateway with auth
web-gateway Axum REST + WebSocket gateway

Frontend

web-dashboard/ -- React 19 + TypeScript + Vite + TradingView charts.

Building

# Check compilation (no PostgreSQL required)
SQLX_OFFLINE=true cargo check --workspace

# Run tests for a specific crate
SQLX_OFFLINE=true cargo test -p <crate> --lib

# Clippy
SQLX_OFFLINE=true cargo clippy --workspace

ML Models

Four production model architectures on Candle v0.9.1 with CUDA:

  • DQN Rainbow -- Deep Q-Network with prioritized replay, dueling heads, noisy nets
  • PPO -- Proximal Policy Optimization with GAE and LSTM policies
  • TFT -- Temporal Fusion Transformer for multi-horizon forecasting
  • Mamba2 -- State space model for sequence prediction

Each model has a standalone trainer and a UnifiedTrainable adapter for the hyperopt pipeline.

Infrastructure

  • Git: Gitea at git.fxhnt.ai (Tailscale-only), Scaleway DEV1-S
  • Observability: OpenTelemetry OTLP (env OTEL_EXPORTER_OTLP_ENDPOINT)
  • Database: PostgreSQL with SQLx offline mode for CI

License

Proprietary. All rights reserved.

Description
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Readme 849 MiB
Languages
Rust 88.2%
Cuda 7.7%
Python 1.3%
Shell 1.1%
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