jgrusewski 790c100719 fix(dqn): wire Q_ABS_REF / Q_DIR_ABS_REF EMA producers per-step (F — kill criterion adaptive floor)
The Q-drift kill criterion's adaptive floor formula is
  max(0.5, 3 × max(ISV[Q_ABS_REF=16], ISV[Q_DIR_ABS_REF=21]))
but smoke-test-n9xzr showed both ISVs stuck at bootstrap 0.05 even
when q_mean reached 0.76 — the producers (q_mag_bin_means_reduce
and q_dir_bin_means_reduce) only fired inside reduce_current_q_stats
at epoch boundary, while the per-step captured update_isv_signals
consumed the resulting scratch buffers each training step.

Concrete failure mode at α=0.05 EMA with raw ≈ 1.0:
- Epoch 0: scratch is zero-initialized, all per-step EMA pulls
  toward zero, ISV[16,21] stay 0.0
- Epoch 0 boundary: reduce_current_q_stats fires, scratch becomes
  q_abs_ref ≈ 1.0, single update_isv_signals writes ISV[16] = 0.05
- Epoch 1+: with stale scratch held constant between boundaries,
  per-step EMA over hundreds of steps would saturate — but smoke
  step counts are small enough (small batch=64, buffer=256) that
  the slot stays near 0.05
- kill_floor degenerates to max(0.5, 3 × 0.05) = 0.5 forever, so
  the criterion fires on legitimate cold-start growth

Fix: launch q_mag_bin_means_reduce + q_dir_bin_means_reduce in
both fused_training paths (captured adam_update_child at ~line 2228
AND ungraphed step-0 fallback at ~line 1465) immediately before
update_isv_signals. Per-step graph replays now read q_out_buf that
forward_child populated this same step, write fresh scratch, and
the captured update_isv_signals consumes it on the same stream.

Per pearl_cold_path_no_exception_to_gpu_drives.md: cold-path EMAs
fire alongside their consumers. Per feedback_no_partial_refactor.md:
graphed and ungraphed paths migrate together — same producer-
consumer contract.

After this fix, the floor will adapt: ISV[16,21] saturate to the
policy's actual q_abs_ref scale within ~60 steps at α=0.05, so by
epoch 2 the floor becomes 3 × ~0.5 = ~1.5, no longer firing on
legitimate cold-start growth.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-04-29 19:10:48 +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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Python 1.3%
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