What is a mining pool? How pooled bitcoin mining works

A mining pool is a group of bitcoin miners who combine their computing power and split the block rewards they earn together. Instead of one miner waiting years for a lucky hit, thousands of machines work as a single team and get paid small, regular amounts in proportion to the work they contribute. Almost all bitcoin mining today happens this way.

Why mining pools exist

In proof of work, miners race to find a block hash below a target set by the network. The winner of each block, found roughly every 10 minutes, collects the block subsidy (3.125 BTC since the April 2024 halving) plus transaction fees. Everyone else gets nothing for that round.

The odds for a small miner are brutal. Total network hashrate was about 1,050 EH/s this month, according to CryptoQuant data. A single modern ASIC miner producing around 200 TH/s holds roughly one five-millionth of that power. At about 52,500 blocks a year, simple maths says it would find a block about once a century on average — and it might be far sooner or far later. Pools turn that lottery into something closer to a salary.

How a pool works, step by step

1. The pool builds the block template. Its servers pick transactions from the mempool and send miners a work package, usually over the Stratum protocol.
2. Miners hash and submit "shares". A share is a hash that meets a much easier target set by the pool. Shares cannot win a block on their own, but they prove how much work each machine is doing.
3. Someone finds the real block. Occasionally one share also meets the network's full difficulty. The block reward is paid to the pool's address, not to the individual miner who found it.
4. The pool pays out. The operator takes its fee and distributes the rest according to its payout scheme, typically once a balance passes a minimum threshold.

Because every share is counted, it does not matter whose machine found the block. A miner with 1% of the pool's hashrate earns about 1% of the pool's rewards over time.

Payout schemes compared

PPS and FPPS pay for every share whether or not the pool finds blocks, so the operator absorbs bad luck and charges more for it. PPLNS pays only when the pool wins, sharing out each block among the last N shares, which rewards miners who stay put and can be more profitable over long periods, but it is less predictable week to week. Some pools offer hybrids such as PPS+.

Mining pools and decentralization

Pools are a practical fix, but they create a concentration question. A handful of pools, led in recent years by Foundry USA and AntPool, account for most of bitcoin's hashrate. In 2014 the pool GHash.io briefly approached half of all hashrate, prompting miners to leave voluntarily.

Two things limit the risk. The pool operator does not own the machines: individual miners can point their hardware elsewhere in minutes, as Binance Pool's customers must do before it closes on 10 November. And newer software such as Stratum V2 lets miners build their own block templates, choosing which transactions go in, rather than leaving that to the pool. Adoption is still limited, but it moves an important power back to miners.

How to choose a mining pool

• Payout scheme and fee. Compare FPPS and PPLNS terms net of fees, not headline fees alone.
• Minimum payout and frequency. Low thresholds matter for small miners.
• Transparency. Look for public stats on blocks found, pool hashrate and luck.
• Server locations. Nearby servers mean lower latency and fewer stale shares.
• Account requirements. Some pools require identity checks; others need only a payout address.
• Track record. Pools can shut down or change terms, so do not let large balances sit unpaid.

There are also "solo" pool services, where you keep the whole block reward (minus a fee) if your own machine finds a block. That is a lottery ticket, not an income.

Is pool mining worth it?

Whether mining pays depends far more on your electricity price, hardware efficiency and bitcoin's price than on the pool. A pool smooths the income; it does not make an unprofitable setup profitable. If you simply want exposure to bitcoin, buying it is usually simpler — our guide on what bitcoin is covers the basics.