6cb2257163
Caps any branch's weight-gradient L2 norm at num_branches × median
(median across the 4 branches' norms). Scales the offending branch's
gradient down to the cap; healthy branches pass through unchanged.
Fixes the observed pathology in L40S train-mdh86: grad_ratio_mag_dir
was 15k–26k× for 6 consecutive epochs, then collapsed to ~100× in a
single step at epoch 7 and destabilised learning (Sharpe flipped +34
→ -67, never recovered). Symmetric per-branch capping at
`num_branches × median` prevents the swing at both ends without
requiring a global ratio bound.
No tuned knobs: `num_branches = 4` is architectural (factored action
space: direction × magnitude × order × urgency), `median_branch_norm`
is a per-step statistical reference that tracks the current gradient
regime, and the product is fully adaptive. Per
feedback_adaptive_not_tuned.md, the only static value is the
architectural axis count; medians and derived caps are signal-driven.
Implementation — two CUDA kernel launches in
`branch_grad_balance_kernel.cu`:
branch_grad_norm_reduce: grid=(4,1,1), block=(256,1,1). One block
per branch; sum-of-squares via shared-mem
tree reduce writes `branch_norms_dev[4]`.
No atomicAdd (one-block-per-branch, single
writer per slot).
branch_grad_rescale: grid=(max_blocks, 4, 1), block=(256,1,1).
Each block caches the 4 branch norms into
shared memory, computes the median via a
5-comparator sorting network + two-element
average (branch-deterministic, no reduction
primitive), derives the 4 per-branch scales
`scale[d] = min(1, 4×median/norm[d])`, then
threads multiply their slice element by the
owning branch's scale. No atomicAdd (each
thread writes one distinct element).
Insertion point: inside the `adam_grad_child` graph between the aux
phase and `compute_grad_norm_for_adam`, so Adam's global clip and the
Adam update both observe the rebalanced gradient. Also wired into the
ungraphed fallback paths so no code path can skip the cap. The kernels
have fixed launch configs, no host syncs, no dynamic allocations —
safe to capture.
Per-branch slice metadata (starts/lens for each of the 4 contiguous
4-tensor branch slices in `grad_buf`) is precomputed from
`compute_param_sizes` at trainer construction and uploaded once to
device i32 buffers, matching the existing `grad_decomp_kernel` layout
convention.
Smoke tests (local RTX 3050 Ti, 4 GB):
magnitude_distribution: PASS (MAG_DIST Q=0.637 H=0.114 F=0.249,
EVAL_DIST Q=0.153 H=0.255 F=0.592)
multi_fold_convergence: PASS (3/3 folds produce best-checkpoint;
fold Sharpes +57.8 / +55.6 / +119.3)
grad_ratio_mag_dir trajectory (mag_dist smoke, first fold, first 5
epochs) — pre-fix values from /tmp/l40s_diag/health.log (L40S
train-mdh86):
pre-fix: 14793, 11934, 12858, 16406, 15141 (×1000 regime)
post-fix: 55, 78, 35, 11, 10 (×10-100 regime)
Three+ orders of magnitude reduction. The residual ratio can still
exceed `num_branches = 4` when the direction branch's norm sits below
the median — the cap bounds each branch's absolute norm (≤ 4×median),
not the pairwise ratio, by design (direction-outlier smallness is a
separate pathology that would be masked by a ratio bound).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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.