[Malleys]

Если много и однотипно, то можно так:

Promise.all([{
	url: "http://etps.mole-pool.net/api/stats",
	id: "etps"
}, {
	url: "http://vic.mole-pool.net/api/stats",
	id: "vic"
}, {
	url: "http://aura.mole-pool.net/api/stats",
	id: "aura"
}].map(
	({url, id}) => fetch(url)
		.then(response => response.json())
		.then(data => {
			let r = data.hashrate;
			let miner = data.minersTotal;
			let exp = r * 1e-6;

			document.getElementById(id + "HR").textContent = exp.toFixed(3);
			document.getElementById(id + "MR").textContent = miner;

			return r;
		})
)).then(rates => {
	alert(rates.reduce((m, v) => m + v));
});