Bitcoin ETF inflows reached about $6.34 billion in the third quarter. This marked their strongest quarter of 2026.
The quarter reversed roughly $5 billion in Q2 net outflows. Bitcoin gained 42.71% during the period. According to CoinGlass, that was its best third quarter since 2017.

Why Bitcoin ETF inflows matter
The funds closed September with $2.65 billion in net inflows. That is down around 25% from $3.52 billion in August. July brought just $172 million. SoSoValue data confirms these figures.

September ended on a weaker note nevertheless. Bitcoin ETFs recorded roughly $149 million in net outflows on Wednesday. This snapped a nine-day inflow streak. That streak had attracted about $3.1 billion.
Ethereum and altcoin ETF flows
US spot Ether ETFs attracted about $3.05 billion in Q3. That followed roughly $714 million in Q2 net outflows. Meanwhile, Ether gained about 71% during the quarter.

Other altcoin funds also drew capital. For example, XRP ETFs attracted $308 million in Q3. Consequently, cumulative net inflows reached $1.79 billion. Solana ETFs drew $272 million in September. Zcash ETFs added $246 million.
What comes next
The quarterly result shows renewed institutional demand. However, September’s weak finish signals caution. Therefore, traders will watch October flows closely. A sustained streak would strengthen the bullish case. A reversal could pressure Bitcoin’s price.