jgrusewski d61aefe2b8 fix(dqn): ISV-driven per-branch grad balancer — equalise via median target
The pre-spec balancer used `cap = 4 × median` to suppress outlier
branches. On L40S train-5wb4n (epoch 9 norms `[dir=130, mag=20000,
ord=18000, urg=16000]`), that made cap = 68000 — exceeding every
branch's norm. No cap ever fired; the kernel was a geometric no-op
for 11 consecutive epochs while direction starved at 1/150 the
magnitude gradient. The outlier-cap algorithm can only handle "one
branch above the pack", not "three co-elevated, one starved".

Replace with ISV-driven equalisation:
  - 4 new ISV slots (31..34): per-branch grad-norm target
  - 1 new ISV slot (35): scale clamp limit
  - ISV_TOTAL_DIM 31 → 36
  - New on-GPU producer kernel `grad_balance_isv_update` runs after
    `branch_grad_norm_reduce`, before `branch_grad_rescale`. Computes
    current-step median + max/min spread, applies adaptive-rate EMA
    to the ISV slots. Single-threaded (1 warp), graph-capture safe,
    no atomicAdd, no host syncs.
  - Rescale kernel now reads ISV target + limit, computes per-branch
    `scale[b] = clamp(target[b] / norm[b], 1/limit, limit)`. Every
    branch equalises toward the shared median target over time;
    starved branches boost, elevated branches suppress. Limit is the
    observed max/min spread EMA, hard-bounded [2.0, 1e4] as a
    numerical-safety cap (not tuning).

Adaptive-rate EMA: `alpha = clamp(err / (err + baseline), 0.01, 0.3)`.
Fast response when error is large relative to current value, slow
drift when stable. No fixed alpha constant.

Bootstrap at construction + fold reset: targets = 1.0, limit = 2.0.
Pre-first-EMA-update behaviour: scale clamped to [0.5, 2.0], effectively
the original identity on warm-up, until real observations flow in.

Complies with feedback_isv_for_adaptive_bounds.md (2026-04-23):
adaptive bounds always live in ISV, never hardcoded. No partial
refactor — all consumers of the balancer contract (launch, kernels,
rescale algorithm) migrate together.

Still pending from the task-#92 triad: (a) C51 backward kernel must
replicate the forward advantage-standardization for d==1 (chain-rule
violation produces wrong gradient; separate commit), (b) IQL
branch_scales floor for direction-branch Hold/Flat starvation
(separate commit). This commit is the safety net; the two root-cause
fixes come next.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-04-23 23:12:53 +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%
PLpgSQL 0.8%
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