How unlikely was it for one solo miner to beat the odds and win a Bitcoin block?

On June 5, 2025, a solo miner pulled off what most would call impossible: solving a Bitcoin block alone and earning over $330,000 in Bitcoin block rewards. 

And they did it during the most competitive mining conditions in Bitcoin’s history.

At the time, Bitcoin’s difficulty was encoded as nBits: 0x1b38a1b5. That string defines the target for miners: The resulting hash of their block must fall below a certain threshold. 

The lower the target, the harder the job. At this level, miners are racing to find a suitable hash out of more than 126 trillion possibilities.

That’s what made this win so unlikely.

Even though the miner in question temporarily inflated their hashrate to around 259 petahashes per second (PH/s) for a short time, it still had a 1 in 3,050 chance of finding a valid block before someone else on the global network. 

Also, unlike industrial mining farms with massive setups, this miner was solo, just one machine submitting hashes through the Solo CKPool.

The miner likely rented a massive burst of computing power for a short time to make it work. It was a calculated gamble, spike the hashrate, take a shot and hope to strike gold

It worked.

Con Kolivas suggests that the solo miner used rental power to inflate its hashrate

Did you know? Solo CKPool, the platform used in this $330,000 win, has recorded fewer than 100 solo block wins in its entire history, making each one a statistical anomaly in a sea of pooled mining dominance.

$330K Bitcoin solo mining 101

What is Bitcoin mining?

Bitcoin mining is the process of verifying transactions and adding them to the blockchain. 

Miners bundle transactions into a block, then repeatedly hash the block header, altering a small “nonce” value until the resulting SHA‑256 double-hash falls below the network’s target. 

That hash target is what the nBits and difficulty encode. The first miner to discover a valid hash earns the reward and sees their block appended, maintaining the ledger and issuing new Bitcoin (BTC).

A typical solo miner setup

Bitcoin mining difficulty 2025 explained

Bitcoin aims to produce one block every 10 minutes to balance security, network synchronization and predictable Bitcoin issuance.

To keep this pace steady despite fluctuations in total network computing power (hashrate), the protocol adjusts difficulty every 2,016 blocks (about every two weeks). 

If block times are consistently faster than 10 minutes, the difficulty increases; if slower, it decreases.

At the time of block 899,826, difficulty was at an all-time high. Bitcoin difficulty visualized

Did you know? In Bitcoin mining, hashrates scale fast: 1 hash is a single guess, a terahash is a trillion, a petahash is a quadrillion, and an exahash is a quintillion. Today, the Bitcoin network processes over 600 exahashes every second; that’s 600 quintillion guesses per second to find the next block.

How a solo miner mined block 899826

A solo miner using rented hash power temporarily spiked to 259 PH/s and successfully mined Bitcoin block 899,826 on June 5, 2025, earning over $330,000 in a rare all-or-nothing win.

Block 899,826 at a glance

  • Confirmed: June 5, 2025, at 03:48 UTC;
  • Transactions included: 3,680;
  • Total reward: 3.125 BTC (base subsidy) ~0.026 BTC (fees) = ~3.151 BTC;
  • USD value at time of confirmation: approximately $330,386.

This block was mined by a single participant via Solo CK (CKPool), a platform that allows individual miners to attempt to find a whole block on their own, without sharing rewards with others. 

According to CKPool administrator Con Kolivas, only one worker was active at the time, strongly suggesting that this wasn’t a standing mining operation but a temporary setup.

Rented hashpower Bitcoin: A tactical hash burst

The miner achieved a peak hashrate of around 259 petahashes per second (PH/s), an unusually high figure for a solo miner. 

This capacity was likely not from in-house hardware but sourced via rented hash power from a cloud mining provider

Kolivas described the strategy as a “take-a-shot” approach: temporarily boosting computational power just long enough to increase the probability of winning a block before returning to baseline activity.

This kind of short-term burst is a growing tactic among independent miners. Cloud mining marketplaces allow users to rent hashrate on demand, which can be directed toward pools like CKPool for solo attempts.

Solo mining Bitcoin profit vs pooling

Unlike mining pools, where participants contribute their hashrate and receive a proportional share of every reward, solo mining is all-or-nothing. 

If a solo miner finds a block, they keep 100% of the reward. If they don’t, they earn nothing. It’s a higher-risk approach (especially when renting capacity), but the potential payoff is significantly larger.

In this case, the strategy succeeded. By combining targeted timing, rented infrastructure and a solo reward model, the miner turned a narrow statistical opportunity into a successful block confirmation worth six figures.

CKPool mining success: Why it matters now

When block 899,826 was solved, Bitcoin’s mining difficulty was at an all-time high. That’s what makes this case, and others like it, so notable.

This wasn’t the only solo success in 2025. Similar wins occurred on Feb. 10 and April 10, each time with block rewards exceeding $300,000. 

While rare, these events suggest a pattern: Solo mining remains possible, particularly when supported by short-term bursts of rented hash power. 

The implications extend beyond the headlines:

  • For small-scale miners, these examples demonstrate that temporary access to high-performance infrastructure can offer a viable path to block rewards (though it requires capital, timing and technical coordination).
  • For mining pools, the strategy may introduce a hybrid approach where miners toggle between steady pooled rewards and occasional solo attempts when conditions align.
  • For cloud mining services, the trend points to growing demand from users seeking on-demand, high-capacity rentals aimed at short-term solo strategies.

While large-scale operations still dominate the network, strategic solo plays are carving out space, proving that even under record difficulty, individual actors can still make an impact.

What solo Bitcoin miner wins tell you about Bitcoin mining

Events like this highlight the increasing adaptability of Bitcoin mining. 

While rising difficulty suggests a maturing and highly secure network, the continued viability of solo mining demonstrates how new tools and tactics are reshaping who gets to participate.

Platforms like Solo CKPool, once seen as a niche lottery-miner plaything, now support rare but significant block wins. 

At the same time, cloud-based hash power markets are enabling miners without extensive infrastructure to engage in targeted, short-term strategies that can yield outsized returns.

Whether these solo wins will become more common remains uncertain. They rely on a mix of timing, capital access and technical execution that’s difficult to replicate. However, their existence is notable, offering a counterpoint to the narrative that mining is only accessible to industrial players.

In the bigger picture, what used to be a matter of raw computational power is also becoming a question of strategy, flexibility and access to infrastructure. 

The odds remain long, but this case shows they are not zero. That alone will keep others trying.