← 返回文章列表
May 21, 2025
5 分鐘閱讀

配對交易中的距離法:Rust實現與分析

配對交易中的距離法:Rust實現與分析
#配對交易
#rust
#演算法交易
#統計套利
#距離法
🔀
Part 1 of 3 · Collection
Statistical Arbitrage & Pairs Trading

距離法在配對交易中因其簡潔高效而備受青睞。這一技術通過統計度量識別資產對,並基於價格關係的背離與收斂進行交易。本文全面分析了基礎與高階距離法方法,併為高頻交易者、演算法開發者、數學家和程式設計師提供了Rust的實用實現。

距離法的理論基礎

距離法為配對交易建立了基於資產間歸一化價格變動的框架。其核心是利用歐氏平方距離來識別歷史上走勢一致的資產,並在其歸一化價格背離超過統計顯著閾值時生成交易訊號[2]。

該方法主要包括兩個階段:

  1. 配對形成——識別統計相關的資產對
  2. 交易訊號生成——基於背離制定入場和離場規則

數學基礎

基礎實現採用歸一化價格序列間的歐氏距離。對於兩個資產的歸一化價格序列X和Y,計算如下:

fn euclidean_squared_distance(x: &[f64], y: &[f64]) -> f64 {
    assert_eq!(x.len(), y.len(), "Time series must have equal length");
    
    x.iter()
        .zip(y.iter())
        .map(|(xi, yi)| (xi - yi).powi(2))
        .sum()
}

該距離度量有助於識別歷史走勢一致的資產,為統計套利機會提供基礎[2]。

基礎距離法實現

資料歸一化

在計算距離前,需對價格資料進行歸一化以保證可比性。常用min-max歸一化:

fn min_max_normalize(prices: &[f64]) -> Vec<f64> {
    if prices.is_empty() {
        return Vec::new();
    }
    
    let min_price = prices.iter().fold(f64::INFINITY, |a, &b| a.min(b));
    let max_price = prices.iter().fold(f64::NEG_INFINITY, |a, &b| a.max(b));
    let range = max_price - min_price;
    
    if range.abs() < f64::EPSILON {
        return vec![0.5; prices.len()];
    }
    
    prices.iter()
        .map(|&price| (price - min_price) / range)
        .collect()
}

尋找最接近的配對

通過計算所有資產組合的歐氏距離,選取距離最小的作為潛在配對:

#[derive(Debug, Clone)]
struct StockPair {
    stock1_idx: usize,
    stock2_idx: usize,
    distance: f64,
}

impl PartialEq for StockPair {
    fn eq(&self, other: &Self) -> bool {
        self.distance.eq(&other.distance)
    }
}

impl Eq for StockPair {}

impl PartialOrd for StockPair {
    fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
        self.distance.partial_cmp(&other.distance)
    }
}

impl Ord for StockPair {
    fn cmp(&self, other: &Self) -> std::cmp::Ordering {
        self.partial_cmp(other).unwrap_or(std::cmp::Ordering::Equal)
    }
}

fn find_closest_pairs(normalized_prices: &[Vec<f64>], top_n: usize) -> Vec<StockPair> {
    let stock_count = normalized_prices.len();
    let mut pairs = BinaryHeap::new();
    
    for i in 0..stock_count {
        for j in (i+1)..stock_count {
            let distance = euclidean_squared_distance(&normalized_prices[i], &normalized_prices[j]);
            
            pairs.push(Reverse(StockPair {
                stock1_idx: i,
                stock2_idx: j,
                distance,
            }));
            
            // Keep only top N pairs
            if pairs.len() > top_n {
                pairs.pop();
            }
        }
    }
    
    // Convert from heap to vector and reverse to get ascending order
    pairs.into_iter().map(|Reverse(pair)| pair).collect()
}

計算歷史波動率

歷史波動率的計算對於設定合適的交易閾值至關重要:

fn calculate_spread_volatility(normalized_price1: &[f64], normalized_price2: &[f64]) -> f64 {
    assert_eq!(normalized_price1.len(), normalized_price2.len());
    
    // Calculate price spread
    let spread: Vec<f64> = normalized_price1.iter()
        .zip(normalized_price2.iter())
        .map(|(p1, p2)| p1 - p2)
        .collect();
    
    // Calculate mean of spread
    let mean = spread.iter().sum::<f64>() / spread.len() as f64;
    
    // Calculate standard deviation
    let variance = spread.iter()
        .map(|&x| (x - mean).powi(2))
        .sum::<f64>() / spread.len() as f64;
    
    variance.sqrt()
}

高階篩選方法

行業分組篩選

將配對篩選限制在同一行業內,可通過選擇經濟相關性更強的資產提升表現:

fn find_industry_pairs(
    normalized_prices: &[Vec<f64>], 
    industry_codes: &[usize], 
    top_n_per_industry: usize
) -> Vec<StockPair> {
    // Group stocks by industry
    let mut industry_groups: std::collections::HashMap<usize, Vec<usize>> = std::collections::HashMap::new();
    
    for (idx, &code) in industry_codes.iter().enumerate() {
        industry_groups.entry(code).or_default().push(idx);
    }
    
    // Find closest pairs within each industry
    let mut all_pairs = Vec::new();
    
    for (_industry_code, stock_indices) in industry_groups {
        let mut industry_pairs = Vec::new();
        
        for i in 0..stock_indices.len() {
            for j in (i+1)..stock_indices.len() {
                let stock1_idx = stock_indices[i];
                let stock2_idx = stock_indices[j];
                let distance = euclidean_squared_distance(
                    &normalized_prices[stock1_idx], 
                    &normalized_prices[stock2_idx]
                );
                
                industry_pairs.push(StockPair {
                    stock1_idx,
                    stock2_idx,
                    distance,
                });
            }
        }
        
        // Sort pairs by distance
        industry_pairs.sort_by(|a, b| a.distance.partial_cmp(&b.distance).unwrap());
        
        // Take top N from each industry
        let top_pairs: Vec<StockPair> = industry_pairs.into_iter()
            .take(top_n_per_industry)
            .collect();
            
        all_pairs.extend(top_pairs);
    }
    
    all_pairs
}

零交叉法

零交叉法識別出頻繁收斂和背離的配對,可能意味著更有利可圖的交易機會:

fn count_zero_crossings(spread: &[f64]) -> usize {
    if spread.len() < 2 {
        return 0;
    }
    
    let mut count = 0;
    for i in 1..spread.len() {
        if (spread[i-1] < 0.0 && spread[i] >= 0.0) || 
           (spread[i-1] >= 0.0 && spread[i] < 0.0) {
            count += 1;
        }
    }
    
    count
}

fn find_zero_crossing_pairs(
    normalized_prices: &[Vec<f64>],
    top_distance_threshold: f64,
    min_crossings: usize
) -> Vec<StockPair> {
    let stock_count = normalized_prices.len();
    let mut qualifying_pairs = Vec::new();
    
    for i in 0..stock_count {
        for j in (i+1)..stock_count {
            let distance = euclidean_squared_distance(&normalized_prices[i], &normalized_prices[j]);
            
            // Only consider pairs with distance below threshold
            if distance < top_distance_threshold {
                // Calculate spread
                let spread: Vec<f64> = normalized_prices[i].iter()
                    .zip(normalized_prices[j].iter())
                    .map(|(p1, p2)| p1 - p2)
                    .collect();
                
                let crossings = count_zero_crossings(&spread);
                
                if crossings >= min_crossings {
                    qualifying_pairs.push(StockPair {
                        stock1_idx: i,
                        stock2_idx: j,
                        distance,
                    });
                }
            }
        }
    }
    
    // Sort by number of crossings (could extend StockPair to include this)
    qualifying_pairs.sort_by(|a, b| a.distance.partial_cmp(&b.distance).unwrap());
    qualifying_pairs
}

歷史標準差篩選

該方法通過優先選擇價差波動性更高的配對,彌補了基礎方法的不足,有助於提升盈利潛力:

fn find_highsd_pairs(
    normalized_prices: &[Vec<f64>],
    top_distance_count: usize,
    min_volatility: f64
) -> Vec<StockPair> {
    let stock_count = normalized_prices.len();
    let mut all_pairs = Vec::new();
    
    for i in 0..stock_count {
        for j in (i+1)..stock_count {
            let distance = euclidean_squared_distance(&normalized_prices[i], &normalized_prices[j]);
            
            // Calculate spread volatility
            let spread: Vec<f64> = normalized_prices[i].iter()
                .zip(normalized_prices[j].iter())
                .map(|(p1, p2)| p1 - p2)
                .collect();
            
            let volatility = calculate_spread_volatility(&normalized_prices[i], &normalized_prices[j]);
            
            if volatility >= min_volatility {
                all_pairs.push(StockPair {
                    stock1_idx: i,
                    stock2_idx: j,
                    distance,
                });
            }
        }
    }
    
    // Sort by distance
    all_pairs.sort_by(|a, b| a.distance.partial_cmp(&b.distance).unwrap());
    
    // Take top N pairs with highest volatility that meet distance criteria
    all_pairs.into_iter().take(top_distance_count).collect()
}

高階方法:皮爾遜相關法

皮爾遜相關法相較於基礎距離法有諸多優勢,其關注收益率相關性而非價格距離[1]。

Rust實現

fn pearson_correlation(x: &[f64], y: &[f64]) -> f64 {
    assert_eq!(x.len(), y.len(), "Arrays must have the same length");
    
    let n = x.len() as f64;
    let sum_x: f64 = x.iter().sum();
    let sum_y: f64 = y.iter().sum();
    let sum_xx: f64 = x.iter().map(|&val| val * val).sum();
    let sum_yy: f64 = y.iter().map(|&val| val * val).sum();
    let sum_xy: f64 = x.iter().zip(y.iter()).map(|(&xi, &yi)| xi * yi).sum();
    
    let numerator = n * sum_xy - sum_x * sum_y;
    let denominator = ((n * sum_xx - sum_x * sum_x) * (n * sum_yy - sum_y * sum_y)).sqrt();
    
    if denominator.abs() < f64::EPSILON {
        return 0.0;
    }
    
    numerator / denominator
}

struct PearsonPair {
    stock_idx: usize,
    comover_indices: Vec<usize>,
    correlations: Vec<f64>,
}

fn find_pearson_pairs(returns: &[Vec<f64>], top_n_comovers: usize) -> Vec<PearsonPair> {
    let stock_count = returns.len();
    let mut all_pairs = Vec::new();
    
    for i in 0..stock_count {
        let mut correlations = Vec::with_capacity(stock_count - 1);
        
        for j in 0..stock_count {
            if i == j {
                continue;
            }
            
            let correlation = pearson_correlation(&returns[i], &returns[j]).abs();
            correlations.push((j, correlation));
        }
        
        // Sort by correlation (highest first)
        correlations.sort_by(|a, b| b.1.partial_cmp(&a.1).unwrap_or(std::cmp::Ordering::Equal));
        
        // Take top N comovers
        let top_comovers: Vec<(usize, f64)> = correlations.into_iter()
            .take(top_n_comovers)
            .collect();
            
        let (comover_indices, correlation_values): (Vec<usize>, Vec<f64>) = 
            top_comovers.into_iter().unzip();
            
        all_pairs.push(PearsonPair {
            stock_idx: i,
            comover_indices,
            correlations: correlation_values,
        });
    }
    
    all_pairs
}

組合構建與Beta計算

皮爾遜方法為每隻股票構建相關性最高的組合,並計算迴歸係數:

fn calculate_beta(stock_returns: &[f64], portfolio_returns: &[f64]) -> f64 {
    let cov_xy = covariance(stock_returns, portfolio_returns);
    let var_x = variance(portfolio_returns);
    
    if var_x.abs() < f64::EPSILON {
        return 0.0;
    }
    
    cov_xy / var_x
}

fn covariance(x: &[f64], y: &[f64]) -> f64 {
    assert_eq!(x.len(), y.len());
    
    let n = x.len() as f64;
    let mean_x: f64 = x.iter().sum::<f64>() / n;
    let mean_y: f64 = y.iter().sum::<f64>() / n;
    
    let sum_cov: f64 = x.iter()
        .zip(y.iter())
        .map(|(&xi, &yi)| (xi - mean_x) * (yi - mean_y))
        .sum();
    
    sum_cov / n
}

fn variance(x: &[f64]) -> f64 {
    let n = x.len() as f64;
    let mean: f64 = x.iter().sum::<f64>() / n;
    
    let sum_var: f64 = x.iter()
        .map(|&xi| (xi - mean).powi(2))
        .sum();
    
    sum_var / n
}

交易訊號生成

兩種方法的最後一步都是基於背離閾值生成交易訊號:

enum TradingSignal {
    Long,
    Short,
    Neutral
}

struct TradePosition {
    stock1_idx: usize,
    stock2_idx: usize,
    signal: TradingSignal,
    entry_spread: f64,
    timestamp: usize,
}

fn generate_trading_signals(
    normalized_prices: &[Vec<f64>],
    pairs: &[StockPair], 
    threshold_multiplier: f64,
    volatilities: &[f64],
    current_time: usize
) -> Vec<TradePosition> {
    let mut positions = Vec::new();
    
    for (pair_idx, pair) in pairs.iter().enumerate() {
        let stock1_idx = pair.stock1_idx;
        let stock2_idx = pair.stock2_idx;
        
        // Calculate current spread
        let current_spread = normalized_prices[stock1_idx][current_time] - 
                             normalized_prices[stock2_idx][current_time];
                             
        let threshold = threshold_multiplier * volatilities[pair_idx];
        
        let signal = if current_spread > threshold {
            // Stock1 is overvalued relative to Stock2
            TradingSignal::Short
        } else if current_spread < -threshold {
            // Stock1 is undervalued relative to Stock2
            TradingSignal::Long
        } else {
            TradingSignal::Neutral
        };
        
        if signal != TradingSignal::Neutral {
            positions.push(TradePosition {
                stock1_idx,
                stock2_idx,
                signal,
                entry_spread: current_spread,
                timestamp: current_time,
            });
        }
    }
    
    positions
}

效能最佳化

對於高頻交易系統,效能至關重要。SIMD(單指令多資料)指令可顯著加速距離計算:

#[cfg(target_arch = "x86_64")]
use std::arch::x86_64::*;

#[cfg(target_arch = "x86_64")]
#[inline]
unsafe fn euclidean_distance_simd(x: &[f32], y: &[f32]) -> f32 {
    assert_eq!(x.len(), y.len());
    
    let mut sum = _mm256_setzero_ps();
    let chunks = x.len() / 8;
    
    for i in 0..chunks {
        let xi = _mm256_loadu_ps(&x[i * 8]);
        let yi = _mm256_loadu_ps(&y[i * 8]);
        
        let diff = _mm256_sub_ps(xi, yi);
        let squared = _mm256_mul_ps(diff, diff);
        sum = _mm256_add_ps(sum, squared);
    }
    
    // Handle the remaining elements
    let mut result = _mm256_reduce_add_ps(sum);
    
    for i in (chunks * 8)..x.len() {
        result += (x[i] - y[i]).powi(2);
    }
    
    result.sqrt()
}

// Helper function to sum SIMD vector
#[cfg(target_arch = "x86_64")]
#[inline(always)]
unsafe fn _mm256_reduce_add_ps(v: __m256) -> f32 {
    let hilow = _mm256_extractf128_ps(v, 1);
    let low = _mm256_castps256_ps128(v);
    let sum128 = _mm_add_ps(hilow, low);
    
    let hi64 = _mm_extractf128_si128(_mm_castps_si128(sum128), 1);
    let low64 = _mm_castps_si128(sum128);
    let sum64 = _mm_add_ps(_mm_castsi128_ps(hi64), _mm_castsi128_ps(low64));
    
    _mm_cvtss_f32(_mm_hadd_ps(sum64, sum64))
}

非同步處理可進一步提升吞吐量,尤其是在處理大量配對時:

use tokio::task;
use futures::future::join_all;

async fn process_pairs_async(
    normalized_prices: &[Vec<f64>],
    stock_count: usize,
    chunk_size: usize
) -> Vec<StockPair> {
    let mut tasks = Vec::new();
    
    // Split work into chunks
    let chunks = (stock_count + chunk_size - 1) / chunk_size;
    
    for chunk in 0..chunks {
        let start = chunk * chunk_size;
        let end = std::cmp::min((chunk + 1) * chunk_size, stock_count);
        
        let prices_clone = normalized_prices.to_vec();
        
        let task = task::spawn(async move {
            let mut pairs = Vec::new();
            
            for i in start..end {
                for j in (i+1)..stock_count {
                    let distance = euclidean_squared_distance(&prices_clone[i], &prices_clone[j]);
                    
                    pairs.push(StockPair {
                        stock1_idx: i,
                        stock2_idx: j,
                        distance,
                    });
                }
            }
            
            pairs
        });
        
        tasks.push(task);
    }
    
    // Await all tasks and combine results
    let results = join_all(tasks).await;
    
    let mut all_pairs = Vec::new();
    for result in results {
        if let Ok(pairs) = result {
            all_pairs.extend(pairs);
        }
    }
    
    // Sort by distance
    all_pairs.sort_by(|a, b| a.distance.partial_cmp(&b.distance).unwrap_or(std::cmp::Ordering::Equal));
    all_pairs
}

策略實現測試

評估實現效果需要合適的測試基礎設施:

#[cfg(test)]
mod tests {
    use super::*;
    
    #[test]
    fn test_normalization() {
        let prices = vec![10.0, 15.0, 12.0, 18.0, 20.0];
        let normalized = min_max_normalize(&prices);
        
        let expected = vec![0.0, 0.5, 0.2, 0.8, 1.0];
        
        for (a, b) in normalized.iter().zip(expected.iter()) {
            assert!((a - b).abs() < 0.001);
        }
    }
    
    #[test]
    fn test_euclidean_distance() {
        let x = vec![0.1, 0.2, 0.3, 0.4, 0.5];
        let y = vec![0.15, 0.22, 0.35, 0.38, 0.53];
        
        let distance = euclidean_squared_distance(&x, &y);
        let expected = 0.0049; // Calculated manually
        
        assert!((distance - expected).abs() < 0.0001);
    }
    
    #[test]
    fn test_pearson_correlation() {
        let x = vec![1.0, 2.0, 3.0, 4.0, 5.0];
        let y = vec![5.0, 4.0, 3.0, 2.0, 1.0];
        
        let corr = pearson_correlation(&x, &y);
        let expected = -1.0; // Perfect negative correlation
        
        assert!((corr - expected).abs() < 0.0001);
    }
    
    // Integration tests would be implemented in tests/ directory
}

整合測試建議遵循Rust慣例,將測試放在專案根目錄下的tests資料夾中[15][18]。

結論

距離法為配對交易提供了堅實的框架,無論是基礎還是高階方法都為統計套利帶來了寶貴機會。基礎方法側重於歐氏距離,簡潔高效;皮爾遜相關法則帶來更高的靈活性和更優的均值迴歸特性。

Rust的高效能特性使其成為實現此類高計算量策略的理想語言,尤其是在SIMD和併發處理最佳化下。統計嚴謹性與高效實現的結合,為演算法交易者打造了強大工具箱。

在實現配對交易系統時,應考慮:

  1. 簡單性(基礎方法)與統計能力(皮爾遜方法)之間的權衡
  2. 大規模配對分析所需的計算資源
  3. 交易成本對盈利能力的重大影響[3]
  4. 配對的持續監控與再校準需求

將距離法與Rust的效能結合,交易者可開發出高效且強大的統計套利系統,滿足現代市場的速度與規模需求。

引用

@software{soloviov2025distanceapproach,
  author = {Soloviov, Eugen},
  title = {Distance Approach in Pairs Trading: Implementation and Analysis with Rust},
  year = {2025},
  url = {https://marketmaker.cc/en/blog/post/distance-approach-pairs-trading},
  version = {0.1.0},
  description = {A comprehensive analysis of basic and advanced Distance Approach methodologies for pairs trading, with practical implementations in Rust tailored for high-frequency traders and algorithmic developers.}
}

參考文獻

  1. Hudson Thames - Introduction to Distance Approach in Pairs Trading Part II
  2. Hudson Thames - Distance Approach in Pairs Trading Part I
  3. Reddit - Pairs Trading is Too Good to Be True?
  4. GitHub - Kucoin Arbitrage
  5. docs.rs - Euclidean Distance in geo crate
  6. Simple Linear Regression in Rust
  7. GitHub - correlation_rust
  8. docs.rs - Cointegration in algolotl-ta
  9. GitHub - trading_engine_rust
  10. docs.rs - distances crate
  11. Reddit - Looking for stats crate for Dickey-Fuller
  12. crates.io - crypto-pair-trader
  13. w3resource - Rust Structs and Enums Exercise
  14. Rust Book - Test Organization
  15. Design Patterns in Rust
  16. GitHub - simd-euclidean
  17. Rust by Example - Integration Testing
  18. YouTube - Integration Testing in Rust
  19. Stack Overflow - Calculate Total Distance Between Multiple Points
  20. Databento - Pairs Trading Example
  21. Rust std - f64 Primitive
  22. Hudson & Thames - Distance Approach Documentation
  23. GitHub - trading-algorithms-rust
  24. docs.rs - linreg crate
  25. Rust Book - References and Borrowing
  26. Stack Overflow - How to Interpret adfuller Test Results
  27. lib.rs - arima crate
  28. Econometrics with R - Cointegration
  29. DolphinDB - adfuller Function
  30. docs.rs - arima crate (latest)
  31. Wikipedia - Cointegration
免責宣告:本文提供的資訊僅用於教育和參考目的,不構成財務、投資或交易建議。加密貨幣交易涉及重大損失風險。

Authors

Eugen Soloviov
Eugen Soloviov

Trading-systems engineer

Trading-systems engineer building bots since 2017: cross-exchange arbitrage (connected up to 30 venues), cointegration-based pairs arbitrage across spot and futures, scalping, news and sentiment-driven strategies, trend algorithms, and portfolio management and balancing algorithms. Also builds sub-millisecond order execution, big-data warehouses, backtesting engines, AI agents, and trading interfaces (incl. open-source profitmaker.cc). Stack: JS/TS, Python, Rust/Zig/Go, DevOps, backend, frontend, architecture.

Newsletter

緊跟市場步伐

訂閱我們的時事通訊,獲取獨家 AI 交易見解、市場分析和平台更新。

我們尊重您的隱私。您可以隨時退訂。