The Weighted Dynamic Arbitrage Graph

You are given a directed weighted graph 𝐺=(𝑉,𝐸) where: 𝑉 represents currency pairs (e.g., EURUSD, GBPUSD, etc.).
𝐸 represents the relationships between the currency pairs (e.g., price ratios, arbitrage opportunities).
Each edge 𝑒(𝑖,𝑗) between nodes 𝑣𝑖 and 𝑣𝑗 has a weight 𝑤(𝑖,𝑗) representing the logarithm of the price ratio between
𝑣𝑖 and 𝑣𝑗.

Problem:
The graph 𝐺 is time-dependent. At each time step 𝑡, the edge weights 𝑤(𝑖,𝑗,𝑡) change according to a function:

𝑤(𝑖,𝑗,𝑡) = log(𝑃𝑖(𝑡)𝑃𝑗(𝑡))−Δ(𝑖,𝑗,𝑡) where: 𝑃𝑖(𝑡) and 𝑃𝑗(𝑡) are the prices of 𝑣𝑖 and 𝑣𝑗 at time 𝑡. Δ(𝑖,𝑗,𝑡) is a dynamic threshold, influenced by volatility.
A negative weight cycle in 𝐺 represents an arbitrage opportunity, where the product of the weights along the cycle is greater than

1: ∏(𝑖,𝑗)∈𝐶𝑒𝑤(𝑖,𝑗,𝑡)>1.

Your goal is to: Identify all negative weight cycles in 𝐺 for 𝑡1 ≤ 𝑡 ≤𝑡2 .

For each negative cycle 𝐶, calculate the maximum profit factor:

Profit(𝐶)=∏(𝑖,𝑗)∈𝐶𝑒𝑤(𝑖,𝑗,𝑡).

Find the most profitable cycle across all time steps 𝑡.

Additional Constraints:

The graph 𝐺 has ∣𝑉∣=28 nodes (one for each currency pair) and ∣𝐸∣=∣𝑉∣×(∣𝑉∣−1)
∣E∣=∣V∣×(∣V∣−1) edges (fully connected directed graph).

Edge weights 𝑤(𝑖,𝑗,𝑡) vary dynamically with 𝑡 according to: Δ(𝑖,𝑗,𝑡)=𝜎𝑖(𝑡)⋅𝜎𝑗(𝑡), where

𝜎𝑖(𝑡) is the standard deviation of prices for 𝑣𝑖 over a rolling window of 20 time steps.

You must use an efficient algorithm (e.g., Bellman-Ford for detecting negative cycles) to handle the graph's dynamic nature.


Code
#define PAIRS 28 // Number of currency pairs

string CurrencyPairs[PAIRS] = {
    "EURUSD", "GBPUSD", "USDJPY", "GBPJPY", "USDCAD", "EURAUD", "EURJPY", 
    "AUDCAD", "AUDJPY", "AUDNZD", "AUDUSD", "CADJPY", "EURCAD", "EURCHF", 
    "EURGBP", "EURNZD", "GBPCAD", "GBPCHF", "NZDCAD", "NZDJPY", "NZDUSD", 
    "USDCHF", "CHFJPY", "AUDCHF", "GBPNZD", "NZDCHF", "CADCHF", "GBPAUD"
};

vars CorrelationMatrix[PAIRS][PAIRS];    // Correlation adjacency matrix
vars ArbitrageMatrix[PAIRS][PAIRS];     // Arbitrage adjacency matrix
vars VolatilityMatrix[PAIRS];           // Volatility levels for each pair
vars DynamicThresholdMatrix[PAIRS][PAIRS]; // Dynamic arbitrage thresholds
vars RiskAdjustedWeights[PAIRS];        // Risk-adjusted portfolio weights
int StateMatrix[PAIRS][3][3];           // Transition matrix for each pair
vars CurrentDrawdown;                   // Current drawdown level
int LookBack = 200;                     // Lookback period for calculations

// Function to calculate correlation between two series
function calculateCorrelation(vars series1, vars series2, int len) {
    var mean1 = SMA(series1, len);
    var mean2 = SMA(series2, len);
    var numerator = 0, denom1 = 0, denom2 = 0;
    for (int i = 0; i < len; i++) {
        numerator += (series1[i] - mean1) * (series2[i] - mean2);
        denom1 += pow(series1[i] - mean1, 2);
        denom2 += pow(series2[i] - mean2, 2);
    }
    return numerator / sqrt(denom1 * denom2);
}

// Initialize the correlation network
function initializeCorrelationNetwork() {
    for (int i = 0; i < PAIRS; i++) {
        for (int j = 0; j < PAIRS; j++) {
            if (i != j) {
                vars series1 = series(price(CurrencyPairs[i]));
                vars series2 = series(price(CurrencyPairs[j]));
                CorrelationMatrix[i][j] = calculateCorrelation(series1, series2, LookBack);
            } else {
                CorrelationMatrix[i][j] = 1; // Self-correlation
            }
        }
    }
}

// Calculate arbitrage opportunities between pairs with dynamic thresholds
function calculateDynamicArbitrage() {
    for (int i = 0; i < PAIRS; i++) {
        for (int j = 0; j < PAIRS; j++) {
            if (i != j) {
                var priceRatio = log(price(CurrencyPairs[i]) / price(CurrencyPairs[j]));
                var threshold = max(0.01, VolatilityMatrix[i] * 0.5); // Dynamic threshold
                DynamicThresholdMatrix[i][j] = threshold;
                ArbitrageMatrix[i][j] = (abs(priceRatio) > threshold) ? priceRatio : 0;
            } else {
                ArbitrageMatrix[i][j] = 0; // No arbitrage within the same pair
            }
        }
    }
}

// Calculate volatility levels for each pair
function calculateVolatilityMatrix() {
    for (int i = 0; i < PAIRS; i++) {
        VolatilityMatrix[i] = StdDev(series(price(CurrencyPairs[i])), LookBack);
    }
}

// Risk adjustment based on drawdown and portfolio composition
function adjustRiskWeights() {
    var TotalWeight = 0;
    for (int i = 0; i < PAIRS; i++) {
        var riskFactor = max(0.1, 1 - CurrentDrawdown / 0.2); // Reduce risk if drawdown exceeds 20%
        RiskAdjustedWeights[i] = (1 / VolatilityMatrix[i]) * riskFactor;
        TotalWeight += RiskAdjustedWeights[i];
    }
    for (int i = 0; i < PAIRS; i++) {
        RiskAdjustedWeights[i] /= TotalWeight; // Normalize weights
    }
}

// Execute trades based on dynamic arbitrage and risk-adjusted weights
function executeDynamicTrades() {
    for (int i = 0; i < PAIRS; i++) {
        for (int j = 0; j < PAIRS; j++) {
            if (ArbitrageMatrix[i][j] != 0) {
                var WeightI = RiskAdjustedWeights[i];
                var WeightJ = RiskAdjustedWeights[j];
                if (ArbitrageMatrix[i][j] > 0) { // Long-Short arbitrage
                    enterLong(CurrencyPairs[i], WeightI);
                    enterShort(CurrencyPairs[j], WeightJ);
                } else if (ArbitrageMatrix[i][j] < 0) { // Short-Long arbitrage
                    enterShort(CurrencyPairs[i], WeightI);
                    enterLong(CurrencyPairs[j], WeightJ);
                }
            }
        }
    }
}

// Track drawdown levels
function monitorDrawdown() {
    CurrentDrawdown = max(0, 1 - (Equity / MaxEquity));
    if (CurrentDrawdown > 0.2) { // Emergency shutdown at 20% drawdown
        exitLong();
        exitShort();
        printf("Emergency risk controls triggered. All positions closed.");
    }
}

// Main trading function
function run() {
    set(PLOTNOW);

    // Update and calculate all matrices
    initializeCorrelationNetwork();
    calculateVolatilityMatrix();
    calculateDynamicArbitrage();
    adjustRiskWeights();
    monitorDrawdown();

    // Execute trades based on advanced analysis
    executeDynamicTrades();
}

Last edited by TipmyPip; 12/24/24 20:39.