Signal Generation

Overview

Signal-based strategies use predictions from ML models or statistical indicators to make trading decisions. NanoARB provides a flexible signal framework for:

Feature-based signal generation
Confidence-based position sizing
Signal validation and filtering
Integration with ML models

Signal Structure

The Signal struct represents a trading signal:

#[derive(Debug, Clone)]
pub struct Signal {
    /// Signal direction: -1 (sell), 0 (neutral), +1 (buy)
    pub direction: i8,
    /// Signal strength (0 to 1)
    pub strength: f32,
    /// Confidence from model
    pub confidence: f32,
    /// Signal timestamp
    pub timestamp: Timestamp,
}

Location: nano-strategy/src/signals.rs:38-49

Creating Signals

use nano_strategy::signals::Signal;
use nano_core::types::Timestamp;

// Buy signal
let buy_signal = Signal::buy(
    0.8,  // strength (0-1)
    0.75, // confidence (0-1)
    Timestamp::now()
);

// Sell signal
let sell_signal = Signal::sell(
    0.6,  // strength
    0.65, // confidence
    Timestamp::now()
);

// Neutral signal (no action)
let neutral = Signal::neutral(Timestamp::now());

Location: nano-strategy/src/signals.rs:52-83

Signal Methods

impl Signal {
    /// Check if signal suggests buying
    pub fn is_buy(&self) -> bool;

    /// Check if signal suggests selling
    pub fn is_sell(&self) -> bool;

    /// Check if signal is neutral
    pub fn is_neutral(&self) -> bool;

    /// Get the side for order placement
    pub fn side(&self) -> Option<Side>;
}

Location: nano-strategy/src/signals.rs:85-112

SignalConfig

Configure signal-based trading:

#[derive(Debug, Clone)]
pub struct SignalConfig {
    /// Minimum confidence threshold
    pub min_confidence: f32,
    /// Minimum prediction magnitude
    pub min_magnitude: f32,
    /// Position sizing based on confidence
    pub confidence_scaling: bool,
    /// Maximum position size (as fraction)
    pub max_position_size: f32,
    /// Target profit in ticks
    pub target_ticks: i64,
    /// Stop loss in ticks
    pub stop_ticks: i64,
}

Location: nano-strategy/src/signals.rs:8-23

Default Configuration

impl Default for SignalConfig {
    fn default() -> Self {
        Self {
            min_confidence: 0.55,
            min_magnitude: 0.001,
            confidence_scaling: true,
            max_position_size: 1.0,
            target_ticks: 10,
            stop_ticks: 5,
        }
    }
}

Location: nano-strategy/src/signals.rs:25-36

SignalStrategy

The SignalStrategy executes trades based on signals:

pub struct SignalStrategy {
    base: BaseStrategy,
    config: SignalConfig,
    instrument_id: u32,
    order_size: u32,
    max_position: i64,
    pending_order: Option<OrderId>,
    last_signal: Option<Signal>,
    next_order_id: u64,
}

Location: nano-strategy/src/signals.rs:114-132

Creating a Signal Strategy

use nano_strategy::signals::{SignalStrategy, SignalConfig};

let config = SignalConfig {
    min_confidence: 0.6,
    min_magnitude: 0.002,
    confidence_scaling: true,
    max_position_size: 1.0,
    target_ticks: 15,
    stop_ticks: 7,
};

let mut strategy = SignalStrategy::new(
    "ml_signal_strategy",
    instrument_id,
    config,
    10,   // order_size
    100,  // max_position
    12.5, // tick_value
);

Location: nano-strategy/src/signals.rs:135-155

Processing Signals

The strategy processes signals and generates orders:

pub fn process_signal(&mut self, signal: &Signal, book: &dyn OrderBook) -> Vec<Order> {
    let mut orders = Vec::new();

    // Don't trade if we have a pending order
    if self.pending_order.is_some() {
        return orders;
    }

    // Check signal confidence
    if signal.confidence < self.config.min_confidence {
        return orders;
    }

    self.last_signal = Some(signal.clone());

    // Check if signal suggests trading
    let side = match signal.side() {
        Some(s) => s,
        None => return orders, // Neutral signal
    };

    // Get current price
    let current_price = match book.mid_price() {
        Some(p) => p,
        None => return orders,
    };

    // Check position limits
    let current_pos = self.base.position();
    let order_qty = self.calculate_order_size(signal, current_pos);

    if order_qty == 0 {
        return orders;
    }

    // Calculate order price
    let order_price = match side {
        Side::Buy => book.best_bid().map_or(current_price, |(p, _)| p),
        Side::Sell => book.best_ask().map_or(current_price, |(p, _)| p),
    };

    let order_id = OrderId::new(self.next_order_id);
    self.next_order_id += 1;

    let order = Order::new_limit(
        order_id,
        self.instrument_id,
        side,
        order_price,
        Quantity::new(order_qty),
        TimeInForce::IOC,
    );

    self.pending_order = Some(order_id);
    orders.push(order);

    orders
}

Location: nano-strategy/src/signals.rs:157-215

Confidence-Based Sizing

Order size scales with signal strength:

fn calculate_order_size(&self, signal: &Signal, current_pos: i64) -> u32 {
    let base_size = if self.config.confidence_scaling {
        (self.order_size as f32 * signal.strength) as u32
    } else {
        self.order_size
    };

    // Check position limits
    let max_buy = (self.max_position - current_pos).max(0) as u32;
    let max_sell = (self.max_position + current_pos).max(0) as u32;

    match signal.side() {
        Some(Side::Buy) => base_size.min(max_buy),
        Some(Side::Sell) => base_size.min(max_sell),
        None => 0,
    }
}

Location: nano-strategy/src/signals.rs:217-234

Example

// With confidence_scaling = true and order_size = 10

// Strong signal (strength = 0.9)
let strong_signal = Signal::buy(0.9, 0.75, Timestamp::now());
let order_size = strategy.calculate_order_size(&strong_signal, 0);
// order_size = 10 * 0.9 = 9 contracts

// Weak signal (strength = 0.5)
let weak_signal = Signal::buy(0.5, 0.65, Timestamp::now());
let order_size = strategy.calculate_order_size(&weak_signal, 0);
// order_size = 10 * 0.5 = 5 contracts

Integration with ML Models

Integrate signals with ML model predictions:

use nano_core::traits::ModelInference;
use nano_strategy::signals::{Signal, SignalStrategy};

// Define your model output
struct ModelPrediction {
    direction: i8,  // -1, 0, or 1
    probability: f32,
    magnitude: f32,
}

// Convert model prediction to signal
fn prediction_to_signal(pred: ModelPrediction) -> Signal {
    if pred.direction > 0 {
        Signal::buy(
            pred.magnitude,
            pred.probability,
            Timestamp::now()
        )
    } else if pred.direction < 0 {
        Signal::sell(
            pred.magnitude,
            pred.probability,
            Timestamp::now()
        )
    } else {
        Signal::neutral(Timestamp::now())
    }
}

// In your trading loop
loop {
    // Get features from order book
    let features = extract_features(&book);

    // Run model inference
    let prediction = model.predict(&features)?;

    // Convert to signal
    let signal = prediction_to_signal(prediction);

    // Process signal
    let orders = strategy.process_signal(&signal, &book);

    // Submit orders
    for order in orders {
        execution_handler.submit_order(order)?;
    }
}

Feature Engineering

Extract features from order book for signal generation:

use nano_core::traits::OrderBook;

pub struct OrderBookFeatures {
    pub mid_price: f64,
    pub spread: f64,
    pub bid_depth: f64,
    pub ask_depth: f64,
    pub imbalance: f64,
    pub volatility: f64,
}

impl OrderBookFeatures {
    pub fn extract(book: &dyn OrderBook) -> Option<Self> {
        let mid = book.mid_price()?.as_f64();
        let spread = book.spread()?.as_f64();

        // Calculate order book imbalance
        let bid_depth = book.bid_depth(5).value() as f64;
        let ask_depth = book.ask_depth(5).value() as f64;
        let total_depth = bid_depth + ask_depth;
        let imbalance = if total_depth > 0.0 {
            (bid_depth - ask_depth) / total_depth
        } else {
            0.0
        };

        Some(Self {
            mid_price: mid,
            spread,
            bid_depth,
            ask_depth,
            imbalance,
            volatility: 0.0, // Calculate from price history
        })
    }

    pub fn to_array(&self) -> Vec<f32> {
        vec![
            self.mid_price as f32,
            self.spread as f32,
            self.bid_depth as f32,
            self.ask_depth as f32,
            self.imbalance as f32,
            self.volatility as f32,
        ]
    }
}

Signal Filtering

Implement filters to improve signal quality:

pub struct SignalFilter {
    min_confidence: f32,
    min_strength: f32,
    max_age_ns: i64,
}

impl SignalFilter {
    pub fn should_trade(&self, signal: &Signal, current_time: Timestamp) -> bool {
        // Check confidence threshold
        if signal.confidence < self.min_confidence {
            return false;
        }

        // Check strength threshold
        if signal.strength < self.min_strength {
            return false;
        }

        // Check signal age
        let age = current_time.as_nanos() - signal.timestamp.as_nanos();
        if age > self.max_age_ns {
            return false;
        }

        // Check for neutral signal
        if signal.is_neutral() {
            return false;
        }

        true
    }
}

Complete Example

use nano_strategy::signals::{Signal, SignalStrategy, SignalConfig};
use nano_core::traits::Strategy;

// Configure the signal strategy
let config = SignalConfig {
    min_confidence: 0.6,
    min_magnitude: 0.002,
    confidence_scaling: true,
    max_position_size: 1.0,
    target_ticks: 15,
    stop_ticks: 7,
};

// Create the strategy
let mut strategy = SignalStrategy::new(
    "my_signal_strategy",
    1, // instrument_id
    config,
    10,   // order_size
    100,  // max_position
    12.5, // tick_value
);

// Trading loop
loop {
    // Extract features
    let features = extract_features(&book)?;

    // Generate signal from ML model
    let prediction = model.predict(&features)?;
    let signal = Signal::buy(
        prediction.strength,
        prediction.confidence,
        Timestamp::now()
    );

    // Process signal and get orders
    let orders = strategy.process_signal(&signal, &book);

    // Submit orders
    for order in orders {
        execution_handler.submit_order(order)?;
    }

    // Handle fills
    if let Some(fill) = execution_handler.next_fill() {
        strategy.on_fill(&fill);
    }

    // Monitor performance
    if let Some(last_signal) = strategy.last_signal() {
        println!("Last signal: direction={}, confidence={:.2}",
                 last_signal.direction, last_signal.confidence);
    }
    println!("Position: {}, P&L: ${:.2}",
             strategy.position(), strategy.pnl());
}

Best Practices

Set appropriate confidence thresholds - Start with min_confidence >= 0.6 to filter weak signals
Use confidence scaling - Let strong signals trade larger sizes:
```
config.confidence_scaling = true;
```

Validate signals before trading - Check age, confidence, and magnitude:

if signal.confidence < 0.6 || signal.strength < 0.5 {
    return Vec::new();
}

Track signal performance - Monitor which signals are profitable:

if let Some(last_signal) = strategy.last_signal() {
    metrics.record_signal_performance(last_signal, strategy.pnl());
}

Combine multiple signals - Aggregate predictions from multiple models:

let combined_signal = combine_signals(vec![signal1, signal2, signal3]);

Signal Sources

Order Book Imbalance

let bid_depth = book.bid_depth(5);
let ask_depth = book.ask_depth(5);
let imbalance = (bid_depth - ask_depth) / (bid_depth + ask_depth);

let signal = if imbalance > 0.2 {
    Signal::buy(imbalance as f32, 0.7, Timestamp::now())
} else if imbalance < -0.2 {
    Signal::sell((-imbalance) as f32, 0.7, Timestamp::now())
} else {
    Signal::neutral(Timestamp::now())
};

Price Momentum

let returns: Vec<f64> = price_history.windows(2)
    .map(|w| (w[1] - w[0]) / w[0])
    .collect();

let momentum = returns.iter().sum::<f64>() / returns.len() as f64;

let signal = if momentum > 0.001 {
    Signal::buy(momentum as f32 * 100.0, 0.65, Timestamp::now())
} else if momentum < -0.001 {
    Signal::sell((-momentum) as f32 * 100.0, 0.65, Timestamp::now())
} else {
    Signal::neutral(Timestamp::now())
};

Get Started

Architecture

Core Concepts

Building Strategies

Backtesting

Data & Features

Deployment

Signal Generation

Overview

Signal Structure

Creating Signals

Signal Methods

SignalConfig

Default Configuration

SignalStrategy

Creating a Signal Strategy

Processing Signals

Confidence-Based Sizing

Example

Integration with ML Models

Feature Engineering

Signal Filtering

Complete Example

Best Practices

Signal Sources

Order Book Imbalance

Price Momentum

Next Steps

RL Strategies

Market Making

Build docs developers (and LLMs) love

Get Started

Architecture

Core Concepts

Building Strategies

Backtesting

Data & Features

Deployment

Documentation Index

​Overview

​Signal Structure

​Creating Signals

​Signal Methods

​SignalConfig

​Default Configuration

​SignalStrategy

​Creating a Signal Strategy

​Processing Signals

​Confidence-Based Sizing

​Example

​Integration with ML Models

​Feature Engineering

​Signal Filtering

​Complete Example

​Best Practices

​Signal Sources

​Order Book Imbalance

​Price Momentum

​Next Steps

RL Strategies

Market Making

Build docs developers (and LLMs) love

Overview

Signal Structure

Creating Signals

Signal Methods

SignalConfig

Default Configuration

SignalStrategy

Creating a Signal Strategy

Processing Signals

Confidence-Based Sizing

Example

Integration with ML Models

Feature Engineering

Signal Filtering

Complete Example

Best Practices

Signal Sources

Order Book Imbalance

Price Momentum

Next Steps