solution.js

const { ethers, Contract } = require('ethers')
const player = require('play-sound')(opts = {})

const rpcURL = 'https://cloudflare-eth.com/'
const provider = new ethers.providers.JsonRpcProvider(rpcURL)

const CONTRACT_ADDRESS = '0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48' // USDC
const CONTRACT_ABI = [{"constant":true,"inputs":[],"name":"name","outputs":[{"name":"","type":"string"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"_spender","type":"address"},{"name":"_value","type":"uint256"}],"name":"approve","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[],"name":"totalSupply","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"_from","type":"address"},{"name":"_to","type":"address"},{"name":"_value","type":"uint256"}],"name":"transferFrom","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[],"name":"decimals","outputs":[{"name":"","type":"uint8"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[{"name":"_owner","type":"address"}],"name":"balanceOf","outputs":[{"name":"balance","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"symbol","outputs":[{"name":"","type":"string"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"_to","type":"address"},{"name":"_value","type":"uint256"}],"name":"transfer","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[{"name":"_owner","type":"address"},{"name":"_spender","type":"address"}],"name":"allowance","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"payable":true,"stateMutability":"payable","type":"fallback"},{"anonymous":false,"inputs":[{"indexed":true,"name":"owner","type":"address"},{"indexed":true,"name":"spender","type":"address"},{"indexed":false,"name":"value","type":"uint256"}],"name":"Approval","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"name":"from","type":"address"},{"indexed":true,"name":"to","type":"address"},{"indexed":false,"name":"value","type":"uint256"}],"name":"Transfer","type":"event"}]
let contract = new Contract(CONTRACT_ADDRESS, CONTRACT_ABI, provider);

// Note: USDC uses 6 decimal places
const TRANSFER_THRESHOLD = 100000000000 // wei

const playSound = () => {
  player.play('ding.mp3', function(err){
    if (err) throw err
  })

}

const main = async () => {
  playSound()
  const name = await contract.name()
  console.log(`Whale tracker started!\nListening for large transfers on ${name}`)

  contract.on('Transfer', (from, to, amount, data) => {
    // Note: not all ERC-20 tokens index `amount`
    // Use this instead of Ethers.js query filters
    // https://docs.ethers.io/v5/concepts/events/
    if(amount.toNumber() >= TRANSFER_THRESHOLD) {
      playSound()
      console.log(`New whale transfer for ${name}: https://etherscan.io/tx/${data.transactionHash}`)
    }

  })
}

main()