jgrusewski 875f263ec9 feat(bf16): f32 backward dX scratch + bf16 staging — eliminates dX truncation
Backward pass dX computation now uses f32 scratch buffers with bf16
staging for the backward chain. Pattern: f32 GemmEx → relu_mask (f32) →
f32→bf16 cast → next layer reads bf16 dY.

Changes:
- 6 bw_d_h_* scratch buffers: CudaSlice<half::bf16> → CudaSlice<f32>
- New bw_dy_bf16_staging: shared bf16 buffer for layer transitions
- backward_fc_layer dX: gemmex_bf16 → gemmex_bf16_acc_f32 (f32 output)
- launch_dx_only: gemmex_bf16 → gemmex_bf16_acc_f32 (f32 with beta)
- relu_mask_kernel: reads/writes f32 (no bf16 clamp needed)
- f32_to_bf16_cast_kernel: ±500 clamp at type boundary (in backward_kernels.cu)
- cast_dx_to_staging: f32 scratch → bf16 staging per layer
- IQN/ensemble backward: bf16→f32 cast for dX input, f32→bf16 for dY output
- bw_d_h_s2_as_bf16(): attention backward receives bf16 via staging

Hyperparameters updated for f32 Adam:
- learning_rate: 1e-5 → 1e-4 (updates must exceed bf16 shadow step ~1e-3)
- adam_epsilon: 1e-3 → 1e-8 (standard Adam, bf16 workaround no longer needed)
- grad_norm NaN skip kept as defense-in-depth (source still under investigation)

895/895 unit + 359/359 ml-dqn tests pass.
7-11/11 smoke tests (intermittent NaN from unknown source — NOT backward dX).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-03-29 12:17:04 +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
No description provided
Readme 849 MiB
Languages
Rust 88.2%
Cuda 7.7%
Python 1.3%
Shell 1.1%
PLpgSQL 0.8%
Other 0.8%