Solo Bitcoin miner wins $222,000 after beating 1 in 100,000 odds

A lone Bitcoin miner using 70 terahashes per second (TH/s) solved block 944,306 on April 9, earning 3.128 BTC worth approximately $222,012. The miner’s hashrate is comparable to a single Bitmain Antminer S17+—a model largely retired by many large-scale operations.

The block reward and mining setup

The payout comprised 3.125 BTC in block subsidy (about $221,800) and 0.003 BTC in transaction fees (about $212). The miner used CKpool’s solo mining software, specifically the European server at eusolo.ckpool.org. CKpool developer Con Kolivas confirmed the event on X, describing the odds as roughly a 1 in 100,000 chance of solving a block per day for a miner of this size.

Independent verification was provided via the Bitcoin explorer Mempool, which tracks block discoveries and associated rewards in real time.

Context: odds, network hashrate, and recent clustering

Bitcoin’s network hashrate was roughly 1.02 zettahashes per second on the day of the discovery. With 70 TH/s, the miner represented about 0.0000069% of the total network hashrate—an extremely small share.

This win also followed another solo block discovery within a short window. The previous solo miner win referenced in the report occurred on block 943,411 around March 30, after a 33-day drought in solo block discoveries. Two solo wins within 10 days reflect statistical clustering that the report notes can be uncomfortable for probability-based expectations.

Solo mining versus industrial mining

Modern Bitcoin mining is dominated by industrial-scale pools. The report states that Foundry USA, AntPool, and ViaBTC collectively control over 65% of Bitcoin’s global hashrate, based on recent data. These pools aggregate thousands of miners and distribute rewards proportionally and consistently.

Solo mining differs in that miners contribute their own hashrate and receive the full block reward if they solve a block. However, the report emphasizes that solo miners typically receive nothing for extended periods.

Difficulty and transaction fees

On April 9, mining difficulty stood at 138.97 trillion. The next difficulty adjustment expected around April 18 was projected to bring difficulty down slightly to 131.10 trillion, but the level remains extremely high for individual miners.

Transaction fees have also fallen sharply. The report says median Bitcoin transaction fees recently dropped to about $0.38, the lowest level since 2017. In that context, the $212 fee component of block 944,306 is described as a minor portion of the total reward.

Implications for mining economics and decentralization

The report argues that two solo wins in 10 days do not indicate a fundamental shift in mining dominance. Large pools still control most of the hashrate, and that concentration is described as deepening rather than reversing.

Still, the events are framed as relevant to the decentralization narrative. Bitcoin’s value proposition depends on the idea that no single entity controls the network. When major pools command a large share of hashrate, the report says the premise can appear less secure—making each solo block win a small but meaningful data point that independent participation has not fully disappeared.

For mining profitability, the report highlights tighter economics following the April 2024 halving, which reduced the block subsidy from 6.25 BTC to 3.125 BTC. Combined with low transaction fees, profitability has been under sustained pressure. The report also notes that public mining companies have responded by scaling up operations and seeking cheaper energy sources, which solo miners typically cannot match.

Investor considerations and expected-value math

For risk-tolerant investors considering solo mining as a side venture, the report provides an expected-value comparison. It estimates that an Antminer S17+ running 24/7 consumes roughly 2,000 watts. At a US average electricity rate of about $0.12 per kWh, that equates to about $5.76 per day, or about $2,100 per year.

With one-in-100,000 daily odds for a $222,000 reward, the report estimates the expected daily value at about $2.22—less than half the daily electricity cost—concluding that solo mining is financially unfavorable on average due to extreme variance.

The report also notes an intangible argument: contributing to Bitcoin’s distributed security model. It frames the decision as personal whether that philosophical benefit outweighs the financial cost.

Bottom line

The report concludes that a miner using equipment most operations consider obsolete collected roughly $222,000 by defying odds estimated at around 300-year frequency. While described as statistically meaningless at scale, the episode is presented as a small proof of concept that Bitcoin’s permissionless design still functions as intended, even as mining remains dominated by industrial-scale players.