Solana exchange-traded funds notched their 12th consecutive week of net inflows in the week ending September 18, taking in $60.7 million, while bitcoin ETFs posted their smallest weekly net inflow since the products launched, according to flow data from SoSoValue and Farside. The split shows how altcoin products are holding investor attention even as the bitcoin trade goes quiet after a stretch of heavy outflows and a failed Senate vote on crypto market structure legislation.
Bitcoin spot ETFs recorded just $6.1 million in net inflows for the full week, the weakest five-session total in the 141 weeks since the funds began trading. Trading volume told the same story. Weekly turnover was the lowest since October 2024, a period when the products were still finding their audience. The week was not uniformly quiet. Friday alone brought $433 million of inflows, led by Fidelity’s FBTC with $310.7 million and BlackRock’s IBIT with $108.4 million, as bitcoin climbed back above $81,000. But that late burst followed three heavy redemption days earlier in the week, including a $746 million outflow session that pushed bitcoin below $80,000 before the rebound. Ether funds finished the week down $140.6 million after those same redemption days outweighed Friday’s $143.7 million inflow.
Altcoin funds keep pulling in cash
Solana’s streak stands out against that backdrop. Twelve straight weeks of inflows is the longest current run among major altcoin ETFs, and the $60.7 million weekly total is modest in absolute terms but consistent. The category’s net assets closed the week near $1.4 billion across the listed funds, with Bitwise’s BSOL among the larger products. Solana itself traded near $111 on Friday, up 2.6 percent on the day, roughly in line with the broader large-cap complex.
XRP funds have been choppy, with most sessions flat and Franklin Templeton’s XRPZ supplying nearly all of the positive flow in recent weeks. Franklin’s fund drew $3.5 million on September 16, the only XRP product with inflows that day, and its cumulative total sits near $483 million. Bitwise received $6.57 million on September 9 and Grayscale $2.11 million the same day, so demand has broadened slightly beyond Franklin at times. Grayscale’s Zcash trust has been the outlier story of the month, accounting for 32.5 percent of spot crypto ETF trading volume in the week ended September 18, an extraordinary share for a single product after ZEC ran to a record above $1,500.
Why bitcoin demand cooled
Several factors converged on the week. The Federal Reserve raised rates 25 basis points on September 16 to a 3.75 to 4.00 percent target range, a hawkish surprise that pushed traders to trim risk across assets. Bitcoin and ether both swung after the decision, and the initial bounce faded within two sessions. The Senate’s failed vote on the CLARITY Act, which would have set a market structure framework for digital assets, removed a near-term catalyst bulls had been counting on. CoinShares and other asset managers have since published notes arguing bitcoin lacks a path above $80,000 into year-end, while VanEck has publicly disagreed with a $100,000 target. The disagreement among issuers is itself a signal that the medium-term outlook is contested.
Corporate treasury buying has slowed too. Glassnode data shows listed companies purchased roughly 5,900 BTC over the past three months, less than 7 percent of a single month’s purchases during 2025, leaving the cohort underwater on average. That channel, which absorbed a large share of supply through the last cycle, has effectively gone quiet at the same time as ETF demand.
“Solana’s ETF machine keeps humming while bitcoin is sleepwalking,” as one flow-tracking summary put it, noting the divergence between the two categories’ weekly totals.
The divergence matters for issuers. Solana products have proven they can attract steady demand without a price breakout, with SOL trading near $111. Bitcoin funds, by contrast, depend more on macro sentiment, and the current mix of higher rates, stalled legislation and quiet corporate buyers has left them idle. Issuers with pending altcoin filings, including for XRP, HYPE and others, will read the Solana streak as evidence that altcoin ETFs can sustain flows even when the flagship asset does not. Grayscale’s Zcash trust took in $233 million since August and announced a 3-for-1 share split, a sign that even mid-cap altcoin products can scale when the underlying asset trends.
There are limits to the comparison. Solana’s weekly totals are small next to what bitcoin funds pulled in during strong weeks earlier this year, and a 12-week streak can end quickly if sentiment turns. The category also benefits from a lower base: fewer products, smaller assets, and flows that move in smaller increments. A single large bitcoin session, like Friday’s $433 million, can dwarf a month of altcoin inflows. Leveraged single-stock products are also muddying the picture. REX Shares and Tuttle Capital launched ASSX, a 2x leveraged ETF tracking bitcoin treasury firm Strive, on Cboe Friday, giving traders another way to take leveraged bitcoin-adjacent exposure without touching the spot funds at all.
Traders will watch whether bitcoin’s Friday rebound extends into a second week of recovery, or whether the $6.1 million weekly figure marks a new baseline for demand heading into the final quarter. The next test comes with the September 19 weekly close and a fresh set of flow data early next week. If Solana extends to 13 weeks while bitcoin posts another near-zero total, the narrative of a rotation within crypto products rather than an exodus from them will harden further. If bitcoin funds recover, the altcoin streak will look less like a trend and more like a placeholder during a quiet stretch.