US Spot Bitcoin ETFs Bought 79,800 BTC in Q3, Nearly Twice New Supply

US spot bitcoin ETFs added 79,800 bitcoin ($6.2 billion) in the third quarter of 2026, nearly twice the 41,300 bitcoin ($2.9 billion) newly mined, according to Glassnode, 21Shares and Bloomberg data as of September 30, 2026. The inflows replaced bitcoin treasury companies as the market's main source of demand and followed $4.8 billion of ETF outflows in the second quarter. Bitcoin rose 42.7% over the quarter to $83,570.

ETF buying was heavily concentrated in two windows, August 17–27 and September 21–25, which accounted for 91% of quarterly inflows measured in bitcoin. Treasury companies, listed firms holding bitcoin on their balance sheets, cut purchases from $7.1 billion in Q2 to roughly $1 billion in Q3. Strategy sold 5,553 bitcoin ($349 million) in July and August, then bought back 7,128 bitcoin ($589 million) from late August, ending the quarter up just 1,665 bitcoin. Combined, ETFs and treasury companies added about $7.2 billion, or 2.4 times the value of newly mined bitcoin, up from 0.8x in Q2, per Strategy filings, Bloomberg, Glassnode and 21Shares.

Who sold into the rally?

Long-term holders — wallets whose coins have not moved in more than 155 days — reduced balances by 248,000 bitcoin ($17.4 billion), nearly three times what ETFs bought, Glassnode data shows. The same cohort had absorbed the downturn, adding $31 billion between November 2025 and June 2026 after the October 10, 2025 crash, while ETFs shed $7.6 billion over that period.

The selling produced gains. Investors realized $9.3 billion in net profits in Q3, the first quarterly net gain of 2026, after $61.6 billion of net realized losses in the first half. Q2 and Q3 combined still show a $12.3 billion net realized loss. Long-term holders' share of supply fell from 74.4% to 73%.

Is price stretched against holder cost?

Not by historical standards. Holder realized price rose only 0.9% to $53,637, putting the MVRV ratio at 1.56x against a median of 1.71x since 2013. But 21Shares analysis flags coins that last moved one to two years ago, acquired at about $97,000, as a level where selling pressure could build; price sits at 0.86 times that cost, roughly 30% of supply remains at a loss, and bitcoin is still 26.7% below its level a year earlier.

How did trading and on-chain activity shift?

Futures took 88.2% of Q3's $4.0 trillion in bitcoin trading volume, up from 86.7% in Q2. Spot volume fell 23% quarter-on-quarter and 53% year-on-year to $470 billion; futures volume fell 7% and 29% to $3.49 trillion. The shift means ETF flows carry more weight in reading demand.

On-chain, transactions rose 46.8% year-on-year to 62.06 million, but adjusted transfer value fell 48.7% to $1.16 trillion. Median transfers averaged $62, down from $152 a year earlier. Daily active addresses fell 11.5% year-on-year to 639,381. The RVT ratio fell 17.8% to 91.3, still twice its year-ago level, and public Lightning capacity dropped 19.3% to 3,767 bitcoin ($310 million).

Did miners return to profit?

September miner income exceeded estimated total mining costs by 6%, ending ten months below breakeven, per Glassnode and the Cambridge Bitcoin Electricity Consumption Index. The model assumes network power at $0.05 per kWh with a 1.5 multiplier, and its exclusion of unprofitable machines tilts estimates toward breakeven. Q3 miner revenue fell 40% year-on-year in dollars but only 3.6% in bitcoin terms; average hashrate fell 4.6% to 918 EH/s. Mining power dropped 17% between October 2025 and July 2026 as weaker operators shut down. The top three pools produced 60.0% of blocks, up from 58.2%, with the largest holding 25.5%.

Fees covered just 0.67% of the network's $2.96 billion Q3 security cost; fees rose 6.5% in the quarter to $19.9 million but fell 54.2% year-on-year, while issuance dilution reached $2.94 billion at an annualized supply growth of roughly 0.8%.

What does the 2028 halving change?

Miner income stood at 1.59 times the power bill in September and 1.06 times full cost, but at September's price and hashrate, the 2028 halving would leave block rewards covering only 80% of the power bill. Reaching the historical minimum of 1.23x since 2018 would require a 54% price rise, a 35% drop in network computing power, or both, 21Shares and Glassnode estimate.

Supportive macro factors for Q4 include the US Treasury doubling long-bond buybacks in September, the Federal Reserve's room to pause after a 25-basis-point September hike, and Bank of America advisors gaining crypto ETP access — a 0.1% allocation from the $10.8 trillion US 401(k) market would equal $10.8 billion. Risks include energy shocks, AI capital competition, a stalled CLARITY Act leaving reform to agency action, and quantum-security questions, where StarkWare has cut the cost of experimental quantum-safe transactions from about $320 to $67. Whether ETF inflows keep outpacing newly mined supply as long-term holder selling slows is the balance to watch through Q4.