Bitcoin ETFs notch best month of 2026 as BTC gains 25% in August

US-listed spot Bitcoin exchange-traded funds (ETFs) capped their best month of 2026 alongside Bitcoin’s biggest monthly gain since November 2024.

Bitcoin ETFs attracted $3.52 billion in net inflows in August, their highest monthly total of 2026 and a sharp increase from just $172 million in inflows in July, according to SoSoValue data.

Bitcoin (BTC) gained about 25% in August, its strongest monthly performance since a 37.29% rally in November 2024, according to CoinGlass.

The August momentum quickly gave way to a weaker start to September, as ETF flows turned negative and Bitcoin briefly fell below $77,000.

August cuts year-to-date outflows by 66% to $1.77B

August’s $3.52 billion in Bitcoin ETF inflows cut year-to-date net outflows by roughly 66%, from $5.29 billion to $1.77 billion.

The biggest monthly outflows came in June at $4.51 billion, followed by $2.43 billion in May and $1.61 billion in January, according to SoSoValue data.

Monthly flows into US spot Bitcoin ETFs in 2026. Source: SoSoValue

The funds recorded net inflows on 16 of 21 trading days in August, including nine consecutive sessions from Aug. 17 through Aug. 27.

Total net assets rose to $99.61 billion at the end of August from $76.29 billion at the end of July, an increase of about 31%. Monthly trading volume climbed nearly 49% to $58.63 billion from $39.37 billion.