Bitcoin Production in September Softens Amid Rising Difficulty — MARA Maintains Lead

Competition in the Bitcoin mining sector intensified in September 2025 as mining difficulty reached new all-time highs, while production across most major miners declined.

Large-scale companies with strong balance sheets and accumulation strategies continued to thrive in this environment, whereas smaller miners faced growing pressure from operational costs and technical volatility.

Bitcoin Production Declines as Difficulty Rises

According to publicly released reports, Cango mined around 616 BTC in September, down from 663 BTC in August.

CleanSpark produced 629 BTC, a slight dip from the previous month. Riot Platforms generated 445 BTC, compared to 477 BTC in August. BitFuFu’s output dropped sharply to 329 BTC, while Marathon Digital Holdings (MARA) maintained its lead with 736 BTC mined, further expanding its Bitcoin reserves.

Bitcoin production by major mining companies. Source: BeInCrypto

The data suggests that while larger miners managed to keep their production relatively stable, smaller operators began to feel the strain from rising difficulty and energy costs.

BTC holdings of selected companies. Source: BeInCrypto

Meanwhile, Bitcoin’s network difficulty climbed to 142.34T in September, marking a new all-time high. This consistent increase in difficulty means that each unit of hashrate now yields fewer BTC, driving hashprice (revenue per unit of computational power) lower.

As a result, miners’ profit margins continue to tighten, especially for those with higher energy costs or less efficient hardware.

Bitcoin mining difficulty. Source: Blockchain.com

Notably, a new anti-Bitcoin mining bill in New York recently proposed a progressive tax on Bitcoin mining companies, with revenue redirected to lower utility bills for residents. The bill faces uncertain prospects but could disrupt multi-billion-dollar data center plans and increase cryptocurrency regulation in the state.

In summary, Bitcoin production in September revealed mounting technical pressure on the mining industry. As difficulty keeps rising and profit margins shrink, large miners like MARA, which have efficient infrastructure and a strategy of BTC accumulation, remain in a strong position.

Smaller firms must carefully consider selling BTC, cutting power capacity, or scaling operations to navigate the increasingly competitive and volatile landscape.