Bitcoin, Ethereum, Solana and XRP spot ETFs each posted net inflows on September 28, combining for roughly $65 million in a single day, according to data from SoSoValue. The synchronized flow across all four wrappers signals that institutional allocation is spreading beyond Bitcoin into the altcoin-based exchange-traded structures that launched later.

Bitcoin products led the day with $31.07 million in net inflows — notably the lowest single-day figure Bitcoin ETFs recorded that month. Ethereum followed with $17.10 million, Solana products took in $12.70 million, and XRP ETFs added $3.96 million.

What do the daily flows look like against cumulative totals?

The one-day numbers are small relative to what the products have absorbed since inception. The cumulative picture, per SoSoValue:

• Bitcoin: $57.58 billion in total net inflows since the January 2024 launch, with $107.82 billion in total net assets — equivalent to 6.42% of Bitcoin's entire market cap held inside regulated ETF wrappers.
• Ethereum: $13.96 billion in cumulative net inflows against $17.69 billion in total net assets, following its May 2024 debut.
• XRP: $1.79 billion in cumulative inflows since launching in late 2025.
• Solana: $1.62 billion in cumulative inflows since its 2025 market entry.

The week ending around September 25 set the stage. Bitcoin ETFs pulled in approximately $2.39 billion that week alone — the largest single-week figure of 2026 — enough to push Bitcoin ETFs' 2026 net flows back into positive territory after earlier redemptions had dragged the year-to-date number negative. Solana set a single-day inflow record of $86.7 million on September 25, three days before the four-asset synchronization.

Why are Solana and XRP products attracting institutional interest?

The issuer lineup competing on fees and product structure includes BlackRock, Fidelity, Bitwise and Grayscale — the same institutional franchise that built out the Bitcoin and Ethereum market.

Solana ETFs carry a structural feature the Bitcoin and Ethereum products currently lack: staking integration. Some Solana ETF structures pass staking yield through to holders, converting a passive index exposure into something closer to a yield-bearing position. For allocators weighing wrapper economics, that distribution mechanic is a meaningful differentiator.

XRP's trajectory reflects a different driver. The asset spent years in regulatory limbo following the SEC's lawsuit against Ripple. With that matter resolved and ETFs now live, pent-up demand from investors who waited for a regulated vehicle is the most straightforward explanation for the $1.79 billion in cumulative inflows accumulated in a relatively short window since the late-2025 launch.

The September 28 data point — positive flows across every major crypto spot ETF simultaneously — suggests the multi-asset allocation thesis has moved from proposal to observable flow behavior. Whether Solana and XRP wrappers can sustain cumulative intake at a pace approaching the Ethereum product's $13.96 billion will be the structural benchmark to watch as their first full calendar years of trading progress.