Bitcoin rally to $84.7K raises hashprice; difficulty signal down

Bitcoin’s price reached $84,751, pushing a theoretical network gross hashprice to about $40.31 per petahash per second per day. A completed difficulty increase on Sept. 19 and an early retarget estimate pointing lower provide contrasting signals for miner revenue.

On Sept. 19 the Bitcoin network difficulty rose from 127.451 trillion to 132.757 trillion at block 967,680, an increase of 4.1634%. A model produced on Sept. 15 set a price threshold of $82,877 to offset the then-expected difficulty rise; the actual price of $84,751 was about 2.26% above that threshold.

Compared with the Sept. 15 model inputs, bitcoin’s price rose about 7.07% while realized difficulty increased 4.16%. The price-to-difficulty ratio improved roughly 2.79%. Using observed fee levels and the frozen BTC price, the calculated gross hashprice was roughly 2.65% above the prior modeled baseline.

The gross hashprice calculation in this analysis uses the 3.125 BTC block subsidy, the average fee observed in a 144-block sample, the frozen BTC price and the network difficulty. In the sampled blocks, fees totaled 2.04858206 BTC across 144 blocks, averaging 0.01422626 BTC per block and representing about 0.45% of the 452 BTC total reward for those blocks.

An early retarget estimate taken when the new difficulty epoch was 14.43% complete pointed to a possible 2.48% drop in difficulty around Oct. 3. Blocks in that early sample averaged 625.3 seconds, or about 10 minutes and 25 seconds, which is slower than the 10-minute target. Bitcoin recalibrates difficulty every 2,016 blocks to restore average block time to roughly 10 minutes, so slower block times in a sample push projected difficulty lower.

Short samples of block timing are noisy because block discovery is a random process. Early-epoch timing can change even if the underlying computing power remains steady. One-month estimates inferred from block production ranged from about 826.1 exahashes per second to 1.053 zettahashes per second, with a current estimate near 937.5 EH/s; those figures are derived from block arrivals and do not directly measure every active mining machine.

The next completed difficulty will depend on changes in bitcoin price, transaction fees and block timing as the epoch progresses. A sustained higher price or larger fee contribution would raise theoretical revenue per unit of hash, while persistently slower block times would push the completed difficulty lower.

Network-level estimates cannot identify which specific operators are profitable or whether particular miners reduced activity. Differences in miner fleet efficiency, power contracts, financing and operating costs mean the same network revenue level affects firms differently. The available data show a modest increase in theoretical gross hashprice after the Sept. 19 retarget and an early retarget estimate pointing to a decline, with fee contribution in the sampled blocks remaining small and the final difficulty change dependent on the rest of the epoch.