const investments = {
  'stock': 2500,
  'bond': 1000,
  'realEstate': 3000,
  'crypto': 500
};

function calculateTotalInvestment() {
  const total = Object.values(investments).reduce((sum, value) => sum + value, 0);
  return total;
}

function updateInvestment(amount, category) {
  if (category in investments) {
    investments[category] += amount;
  }
}

function displayInvestments() {
  console.log("Current Investments:");
  console.log(`Stock: $${investments.stock}`);
  console.log(`Bond: $${investments.bond}`);
  console.log(`Real Estate: $${investments.realEstate}`);
  console.log(`Crypto: $${investments.crypto}`);
  console.log("\nTotal Investment Value: $${calculateTotalInvestment()}");
}

// Example usage
displayInvestments();
updateInvestment(500, 'stock');
displayInvestments();