jgrusewski 21b6058e07 docs(sp4): close all carve-outs — weight decay + L1 lambda fully signal-driven
Folds two new producer signals into SP4 scope, eliminating the earlier
"carved out" exception:

WEIGHT DECAY (per param-group, 7 new ISV slots):
  λ = |w·g| / max(||w||², ε)
Derived from equilibrium analysis of d/dt(||w||²) = 2(w·g) - 2λ||w||².
The equilibrium gradient-projection-onto-weight-direction divided by
weight norm. Same theoretical-derivation category as Adam β values.
EMA half-life α=0.005 (~140 steps). Bootstrap 1.0.

L1 LAMBDA (trunk only, 1 new ISV slot — NOVEL PEARL):
  λ = (mean(|g|) / mean(|w|)) × D
  where D = (log K - H_observed) / log K  is gradient-direction entropy deficit
  and H_observed = -Σ p[i]·log p[i],  p[i] = ||g[:,i]|| / Σ ||g[:,j]||

L1 regularization-strength derives from gradient-direction entropy
deficit across input features. When gradient is uniform across features
(D≈0): network hasn't differentiated, λ=0 (no pruning). When gradient
concentrates on few features (D≈1): network has identified what matters,
λ ramps up to prune the rest. Self-curriculum — L1 strength tracks the
emergence of feature differentiation.

This extends pearl_adaptive_moe_lambda (regularization strength = EMA-
tracked deficit of regularized quantity) to feature-redundancy domain.
Pearl-name candidate (post-validation): pearl_signal_driven_regularisation_strength.

Bootstrap λ=0 means cold-start = no L1 pruning; ramp-up only after
gradient differentiates. Worst-case behavior is "L1 disabled" — graceful.

Total ISV slot count: 28 → 36. Total producer kernels: 28 → 36.
Effort estimate: 3000-4000 → 3500-4500 LOC, 1-1.5 → 1.5-2 weeks.

Acknowledged limitations updated: removed item #8 (carve-out) since
no carve-outs remain. Added items for L1 pearl novelty (untested) and
weight decay equilibrium-formula non-stationarity. Both have graceful
worst-case behavior and explicit validation criteria (#10 and #11) to
detect anomalies.

SP4 now closes 100% of the magnitude/regularization surface — no
hardcoded scalars remain in the entire chain. AdamW config fields for
weight_decay and l1_lambda removed from HyperParams to prevent
accidental hardcoding regression.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-04-30 21:12:05 +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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