https://firsthandbitcoin.com/blog Bitcoin miner reviews, field reports, outlooks and mining data, written by an operator. en Wed, 30 Sep 2026 00:08:54 GMT https://firsthandbitcoin.com/blog/bitcoin-difficulty-still-below-peak-2026https://firsthandbitcoin.com/blog/bitcoin-difficulty-still-below-peak-2026Tue, 29 Sep 2026 12:00:00 GMTData insightBitcoin has recovered most of this year's losses since its June low. Mining difficulty, which measures how much machinery is actually competing for each block, has not: it is still 15% below the record it set in October, even after three straight increases. Here is what the gap between the two means for anyone running a machine today. https://firsthandbitcoin.com/blog/bitget-hack-north-korea-evidencehttps://firsthandbitcoin.com/blog/bitget-hack-north-korea-evidenceTue, 29 Sep 2026 12:00:00 GMTNewsBitget's CEO suspected North Korea within hours of its $351.6 million hack on 24 September. By the next day, the blockchain-forensics firm Elliptic had the evidence: stolen funds moving through the same addresses that laundered 2025's $1.5 billion Bybit heist, the one the FBI already pinned on Pyongyang. https://firsthandbitcoin.com/blog/whatsminer-m63-has-stopped-once-and-moved-once-in-two-yearshttps://firsthandbitcoin.com/blog/whatsminer-m63-has-stopped-once-and-moved-once-in-two-yearsTue, 29 Sep 2026 12:00:00 GMTProgress reportAt 20 J/TH the M63 is the kind of hardware a weak hashprice tests first, and 2026 tested it: it stood switched off in March and crossed to cheaper power in May. Here is what it has banked and what the forward figures say. https://firsthandbitcoin.com/blog/the-antminer-s19-xp-mined-through-the-halving-before-it-ever-left-argentinahttps://firsthandbitcoin.com/blog/the-antminer-s19-xp-mined-through-the-halving-before-it-ever-left-argentinaTue, 29 Sep 2026 12:00:00 GMTField reportBitmain's first 5-nanometre miner shipped into the worst ASIC market on record, on the strength of a chip nobody had put in a bitcoin machine before. Ours spent more than two years at one site, rode the subsidy cut straight through, and only crossed to cheap power once the numbers stopped being close. https://firsthandbitcoin.com/blog/bitcoin-busiest-year-lowest-fees-in-a-decade-2026https://firsthandbitcoin.com/blog/bitcoin-busiest-year-lowest-fees-in-a-decade-2026Tue, 29 Sep 2026 12:00:00 GMTData insightThe chain has averaged 578,000 transactions a day in 2026, more than any year before it, and the typical one pays about 41 cents. Fees are 0.6% of what miners earn, the lowest since 2015, and almost all of the rest is the subsidy that halves in 2028. https://firsthandbitcoin.com/blog/what-a-mining-pool-is-and-why-your-machine-uses-onehttps://firsthandbitcoin.com/blog/what-a-mining-pool-is-and-why-your-machine-uses-oneTue, 29 Sep 2026 12:00:00 GMTGuideOn its own, one Antminer S21 would find a bitcoin block about once in 89 years. A pool puts many machines to work on the same block and pays each by its share of the effort, which turns a lottery into a small daily payment to your wallet. https://firsthandbitcoin.com/blog/bitcoin-funding-negative-after-squeezehttps://firsthandbitcoin.com/blog/bitcoin-funding-negative-after-squeezeTue, 29 Sep 2026 12:00:00 GMTData insightOn 21 September, annualised funding on the bitcoin perpetual hit 20.7%, its highest reading of the whole rally, as traders borrowed to chase the price rather than being forced to cover a losing short. Four days later it was negative. Open interest fell with it. The price barely did. https://firsthandbitcoin.com/blog/bitmain-antminer-s23-hyd-reviewhttps://firsthandbitcoin.com/blog/bitmain-antminer-s23-hyd-reviewTue, 29 Sep 2026 12:00:00 GMTMachine reviewThe second-most efficient hydro machine we stock, 563 TH/s from 5,349 W at 9.5 J/TH, in Bitmain's newest single-box water-cooled chassis. It has run in our UAE water plant since May 2025, and no public failure record exists for it yet — the honest gap in an otherwise strong machine. https://firsthandbitcoin.com/blog/the-s19e-xp-hyd-was-less-efficient-than-the-s19-xp-hyd-it-was-named-forhttps://firsthandbitcoin.com/blog/the-s19e-xp-hyd-was-less-efficient-than-the-s19-xp-hyd-it-was-named-forTue, 29 Sep 2026 12:00:00 GMTField reportBitmain put it on sale in May 2024, just over two years after the S19 XP Hyd — and gave it a worse efficiency number, 22 J/TH against 20.8. We bought one once the price had settled, ran it at our water site, and it crossed to cheap power in Nigeria before it had spent a year there. https://firsthandbitcoin.com/blog/canaan-avalon-a15-pro-reviewhttps://firsthandbitcoin.com/blog/canaan-avalon-a15-pro-reviewTue, 29 Sep 2026 12:00:00 GMTMachine reviewCanaan's first machine on our floor: 221 TH/s at 16.6 J/TH, from the company that sold the very first bitcoin ASIC in 2013. A solid, mid-pack air-cooled machine at a genuinely cheap entry price, not the most efficient thing we sell. https://firsthandbitcoin.com/blog/bitget-hot-wallet-hackhttps://firsthandbitcoin.com/blog/bitget-hot-wallet-hackFri, 25 Sep 2026 12:00:00 GMTNewsAn exchange's own security systems caught the theft within minutes and its own protection fund says it can cover it in full. Both of those claims are worth taking seriously and worth checking, and neither one is a reason a miner's coins were ever near the wallets in question. https://firsthandbitcoin.com/blog/bitmain-antminer-s21j-xp-hyd-reviewhttps://firsthandbitcoin.com/blog/bitmain-antminer-s21j-xp-hyd-reviewFri, 25 Sep 2026 12:00:00 GMTMachine reviewThe S21j XP Hyd puts 495 TH/s in the same 410×170×209 mm box Bitmain has sold since 2024, at an unchanged 12.0 J/TH. Six months after launch it is already the cheapest entry into that efficiency class we sell, hydro-cooled and built for a purpose-made room. https://firsthandbitcoin.com/blog/every-forward-projection-assumes-the-old-high-returnshttps://firsthandbitcoin.com/blog/every-forward-projection-assumes-the-old-high-returnsFri, 25 Sep 2026 12:00:00 GMTGuideEvery outlook and review on the site prices a machine's future coins at bitcoin's previous all-time high, not today's, and runs that number to the halving expected in April 2028. That looks generous. The quieter alternative — assuming a price bitcoin already reached is never reached again — is the assumption nobody notices they'd be making instead. https://firsthandbitcoin.com/blog/bitcoin-september-curse-2026https://firsthandbitcoin.com/blog/bitcoin-september-curse-2026Wed, 23 Sep 2026 12:00:00 GMTData insightSeptember is supposed to be bitcoin’s worst month, and for years it was. This year it is up 10% with a week to go, the best September in the thirteen years we have prices for. Here is what the record shows, and what it meant for anyone mining through it. https://firsthandbitcoin.com/blog/bitcoin-short-squeeze-etf-inflows-2026https://firsthandbitcoin.com/blog/bitcoin-short-squeeze-etf-inflows-2026Wed, 23 Sep 2026 12:00:00 GMTData insightTwo things happened at once this autumn. Traders who had bet on bitcoin falling were forced to buy it back, and money poured back into the US spot ETFs after most of a year of net outflows. The data shows which one lasted. https://firsthandbitcoin.com/blog/bitcoin-macro-paradox-5-percent-yieldshttps://firsthandbitcoin.com/blog/bitcoin-macro-paradox-5-percent-yieldsWed, 23 Sep 2026 12:00:00 GMTData insightIn the same week the ten-year Treasury yield closed at 5% for the first time since 2007 and the Federal Reserve raised rates, bitcoin began a 14% climb. Every textbook says a 5% risk-free rate should starve an asset that pays no income. This is what the data says instead. https://firsthandbitcoin.com/blog/a-failed-hashboard-is-a-line-item-not-a-catastrophehttps://firsthandbitcoin.com/blog/a-failed-hashboard-is-a-line-item-not-a-catastropheTue, 22 Sep 2026 12:00:00 GMTGuideEvery mining machine develops faults eventually. Whether that is frightening or routine has very little to do with the machine, and almost everything to do with where it is racked and who is standing next to it. https://firsthandbitcoin.com/blog/antminer-s23e-hyd-2u-suspiciously-cheaphttps://firsthandbitcoin.com/blog/antminer-s23e-hyd-2u-suspiciously-cheapMon, 21 Sep 2026 12:00:00 GMTOutlookSame generation as the S23 Hyd, almost the same efficiency, and a fraction of the price per terahash. We went looking for the catch. https://firsthandbitcoin.com/blog/antminer-s23-xp-hyd-first-antminer-under-9-jth-who-is-it-forhttps://firsthandbitcoin.com/blog/antminer-s23-xp-hyd-first-antminer-under-9-jth-who-is-it-forSun, 20 Sep 2026 12:00:00 GMTOutlookUnveiled in Hong Kong in August and shipping from November, it will make the cheapest bitcoin of any machine Bitmain has announced. It also costs more per terahash than almost anything else we would put in the same room. Both facts are the point. https://firsthandbitcoin.com/blog/we-bought-the-whatsminer-m50s-the-week-it-was-replacedhttps://firsthandbitcoin.com/blog/we-bought-the-whatsminer-m50s-the-week-it-was-replacedSat, 19 Sep 2026 12:00:00 GMTField reportSix months before the halving, at a settled price, in the same week MicroBT unveiled its successor. The months before April 2024 did the heavy lifting; one crossing to Nigeria did the rest. https://firsthandbitcoin.com/blog/whatsminer-m7ds-bets-everything-on-densityhttps://firsthandbitcoin.com/blog/whatsminer-m7ds-bets-everything-on-densityFri, 18 Sep 2026 12:00:00 GMTOutlook680 TH/s from a single air-cooled box — more than double an S21 XP — at 13.53 J/TH. MicroBT is not chasing the efficiency crown this generation. It is chasing the cost of everything that is not electricity. https://firsthandbitcoin.com/blog/bitdeer-a4-pro-air-best-first-year-return-on-the-boardhttps://firsthandbitcoin.com/blog/bitdeer-a4-pro-air-best-first-year-return-on-the-boardThu, 17 Sep 2026 12:00:00 GMTOutlook336 TH/s at 10.9 J/TH, air-cooled, and one of the strongest first-year returns on our board. Bitdeer has gone from irrelevant to leading in two generations, and the A2 Pro is the reason to take it seriously. https://firsthandbitcoin.com/blog/six-years-in-the-original-antminer-s19-still-knows-when-to-switch-onhttps://firsthandbitcoin.com/blog/six-years-in-the-original-antminer-s19-still-knows-when-to-switch-onWed, 16 Sep 2026 12:00:00 GMTField reportBought in the summer of 2020, run through the 2021 bull market on a high-uptime site, moved once to Nigeria in 2023 — and still mining on the days the numbers say it should. https://firsthandbitcoin.com/blog/what-the-antminer-s23-will-do-judged-by-the-s19-and-s21https://firsthandbitcoin.com/blog/what-the-antminer-s23-will-do-judged-by-the-s19-and-s21Tue, 15 Sep 2026 12:00:00 GMTOutlookThe base air-cooled model of each Bitmain generation has followed the same arc for three cycles. Here is where the S23 lands if it follows the fourth — and on the numbers, it lands well. https://firsthandbitcoin.com/blog/antminer-s23-hyd-cheapest-bitcoin-we-have-measuredhttps://firsthandbitcoin.com/blog/antminer-s23-hyd-cheapest-bitcoin-we-have-measuredMon, 14 Sep 2026 12:00:00 GMTProgress reportAbout a third less electricity per coin than anything from the S21 generation. Fifteen months of running one, and what 9.5 J/TH does to the arithmetic. https://firsthandbitcoin.com/blog/bitmain-antminer-s21e-xp-hyd-3u-reviewhttps://firsthandbitcoin.com/blog/bitmain-antminer-s21e-xp-hyd-3u-reviewSun, 13 Sep 2026 12:00:00 GMTMachine reviewTwo water-cooled S21e XP machines in one 19-inch rack chassis: 860 TH/s at 13 J/TH. It needs a purpose-built site, and that narrow market is exactly why it is one of the cheapest ways into water-cooled hashrate we can sell. https://firsthandbitcoin.com/blog/antminer-s21-plus-hyd-best-returning-machine-on-our-floorhttps://firsthandbitcoin.com/blog/antminer-s21-plus-hyd-best-returning-machine-on-our-floorSat, 12 Sep 2026 12:00:00 GMTProgress report395 TH/s from one box at a settled entry price, and one of the strongest first-year returns we host. Seventeen months in, here is what it has banked and what is left in it. https://firsthandbitcoin.com/blog/a-machine-crosses-to-cheap-power-oncehttps://firsthandbitcoin.com/blog/a-machine-crosses-to-cheap-power-onceFri, 11 Sep 2026 12:00:00 GMTGuideEveryone agrees that ageing machines should move to cheaper electricity. The hard part is when: not in a lull, not after the machine starts losing money, and never back again when the market turns. https://firsthandbitcoin.com/blog/antminer-s21-plus-eighteen-months-inhttps://firsthandbitcoin.com/blog/antminer-s21-plus-eighteen-months-inThu, 10 Sep 2026 12:00:00 GMTProgress reportOn track to cover its hardware well before the halving, and at the best entry price it has ever had. Here is what it has done so far and what the next two years look like. https://firsthandbitcoin.com/blog/the-whatsminer-m60-had-the-worst-timinghttps://firsthandbitcoin.com/blog/the-whatsminer-m60-had-the-worst-timingWed, 09 Sep 2026 12:00:00 GMTField reportLanded six weeks after the halving at 19.9 J/TH, into the hardest market a new machine could walk into. It is still clearing its power — in Nigeria, not Argentina — and still on track to cover its box. https://firsthandbitcoin.com/blog/the-price-of-a-miner-is-not-the-price-of-the-boxhttps://firsthandbitcoin.com/blog/the-price-of-a-miner-is-not-the-price-of-the-boxTue, 08 Sep 2026 12:00:00 GMTGuideThe sticker price of a mining machine is the smallest honest number in the deal. Freight, duty, customs, cooling plant and setup all sit between the box and its first hash — and they quietly change which machine is actually the cheaper one. https://firsthandbitcoin.com/blog/what-910-days-on-an-antminer-s21-producedhttps://firsthandbitcoin.com/blog/what-910-days-on-an-antminer-s21-producedMon, 07 Sep 2026 12:00:00 GMTField reportBought once its price settled, moved to cheaper power the moment that paid better, and still clearing comfortably today. The S21 is the closest thing this industry has to a boring machine, and that turned out to be the point. https://firsthandbitcoin.com/blog/efficiency-decides-how-many-halvings-a-machine-surviveshttps://firsthandbitcoin.com/blog/efficiency-decides-how-many-halvings-a-machine-survivesSun, 06 Sep 2026 12:00:00 GMTGuideJoules per terahash looks like a spec-sheet detail. It is the one number that decides whether a machine is still worth switching on after the next halving, and it explains why an old machine and a new one can both be good buys. https://firsthandbitcoin.com/blog/antminer-s17-crossed-the-atlantic-oncehttps://firsthandbitcoin.com/blog/antminer-s17-crossed-the-atlantic-onceSat, 05 Sep 2026 12:00:00 GMTField reportThree and a half years on a high-uptime site, straight through the best market the network has ever had, and then one crossing to cheap power when a full year of figures said it belonged there. It mined until November 2025, and the coins are all still here. https://firsthandbitcoin.com/blog/nobody-wanted-the-antminer-t21https://firsthandbitcoin.com/blog/nobody-wanted-the-antminer-t21Fri, 04 Sep 2026 12:00:00 GMTField reportBitmain’s unglamorous budget line, overlooked by most buyers. Two and a half years later it has covered most of its hardware and is on track to cover all of it well before the halving. https://firsthandbitcoin.com/blog/bitdeer-sealminer-a2-pro-air-reviewhttps://firsthandbitcoin.com/blog/bitdeer-sealminer-a2-pro-air-reviewThu, 03 Sep 2026 12:00:00 GMTMachine reviewBitdeer’s first genuinely competitive air-cooled machine: 14.9 J/TH, quieter and lighter than the Antminers it competes with, and it hits its rated efficiency. The open question is how it ages, because almost nobody has run one for two years yet. https://firsthandbitcoin.com/blog/nobody-sells-the-coins-to-pay-the-power-billhttps://firsthandbitcoin.com/blog/nobody-sells-the-coins-to-pay-the-power-billWed, 02 Sep 2026 12:00:00 GMTGuideRun the same machine at the same site two ways and you end up in two different businesses. One sells a little bitcoin every day to cover the electricity. The other keeps every coin and pays for power some other way. Serious miners run the second. https://firsthandbitcoin.com/blog/antminer-s19-xp-hyd-cheapest-coin-of-its-generationhttps://firsthandbitcoin.com/blog/antminer-s19-xp-hyd-cheapest-coin-of-its-generationTue, 01 Sep 2026 12:00:00 GMTField reportThe cheapest bitcoin of anything from its era we have measured. Three years of a hydro machine that nobody was watching. https://firsthandbitcoin.com/blog/bitmain-antminer-s21-xp-reviewhttps://firsthandbitcoin.com/blog/bitmain-antminer-s21-xp-reviewSat, 29 Aug 2026 12:00:00 GMTMachine reviewThe most efficient air-cooled machine we stock, and the one we put S19-era buyers into. At 13.5 J/TH it makes a bitcoin for roughly 40% less electricity than the machine it usually replaces. https://firsthandbitcoin.com/blog/bitmain-antminer-s21-pro-reviewhttps://firsthandbitcoin.com/blog/bitmain-antminer-s21-pro-reviewThu, 27 Aug 2026 12:00:00 GMTMachine reviewThe best purchase on our floor: 234 TH/s at 15 J/TH at a settled price — a machine that covers its own hardware by the next halving and keeps clearing at our rates well beyond it. https://firsthandbitcoin.com/blog/machines-are-the-roof-not-the-buildinghttps://firsthandbitcoin.com/blog/machines-are-the-roof-not-the-buildingTue, 25 Aug 2026 12:00:00 GMTGuideMost people look at a bitcoin miner the way they look at a stock, and it leads them to every wrong conclusion. Look at it the way a landlord looks at a rental property and the whole business snaps into focus. https://firsthandbitcoin.com/blog/antminer-s9-switched-off-its-bitcoin-never-washttps://firsthandbitcoin.com/blog/antminer-s9-switched-off-its-bitcoin-never-wasMon, 24 Aug 2026 12:00:00 GMTField reportBought in the 2018 bear market, sent to cheaper power when a year of figures said it belonged there, and run until even 3.9¢ stopped paying. Every coin it made is still in the wallet — and they are the cheapest coins we have. https://firsthandbitcoin.com/blog/mining-with-an-antminer-s19k-pro-since-launchhttps://firsthandbitcoin.com/blog/mining-with-an-antminer-s19k-pro-since-launchSat, 22 Aug 2026 12:00:00 GMTField reportBought once its price settled after launch, racked in Argentina at 6¢, run through a halving, and moved to Nigeria once cheap power had spent a year paying decisively better. Not one sat sold — and it has already covered its own hardware. https://firsthandbitcoin.com/blog/bitmain-antminer-s19k-pro-reviewhttps://firsthandbitcoin.com/blog/bitmain-antminer-s19k-pro-reviewThu, 20 Aug 2026 12:00:00 GMTMachine reviewThree years in, it has covered its own hardware and is still mining. That works on cheap power. What you are buying is 23 J/TH and a hashboard failure rate operators put in the single digits inside six months.