The landscape for cryptocurrency exchange-traded funds (ETFs) is evolving quickly in 2025, and altcoins are now at the center of this transformation. While Bitcoin and Ethereum ETFs have already made headlines, the focus is shifting toward a new group of digital assets that could soon gain approval from the U.S. Securities and Exchange Commission (SEC). According to the latest forecasts from Bloomberg ETF analysts, altcoins such as Solana, Litecoin, and XRP are leading the pack, and the chances of regulatory approval are stronger than ever.

In what analysts are calling the possible start of an “Altcoin ETF Summer,” asset managers, traders, and regulators are all preparing for a major shift. The approval of spot ETFs for leading altcoins could mark a new era for cryptocurrency investments in the United States.

Solana, Litecoin, and Index Funds Lead the Way

A recent report from Bloomberg’s ETF analyst team, including James Seyffart and Eric Balchunas, suggests that Solana, Litecoin, and crypto index funds now hold the highest probability of getting SEC approval in 2025. Based on regulatory patterns, filing deadlines, and market readiness, these categories are estimated to have a 90% chance of approval within the next few months.

The applications have already been submitted by major financial firms such as Grayscale, Bitwise, Franklin Templeton, VanEck, and Hashdex. These companies are well-known in both traditional finance and crypto markets and have been actively pushing to expand their ETF offerings beyond Bitcoin and Ethereum.

What’s especially significant is that the SEC has now formally acknowledged several of these filings. That means they are no longer in limbo but are under active review, with final decision deadlines ranging from mid-2025 to late 2025.

XRP Isn’t Far Behind

While Solana and Litecoin are leading, XRP isn’t far behind. Bloomberg analysts have assigned XRP an 85% likelihood of receiving spot ETF approval before the end of the year. This is a sharp rise in confidence, likely influenced by Ripple’s partial legal victory in 2023, where a U.S. court ruled that XRP sales to retail investors did not constitute securities transactions.

Several major asset managers, including ProShares and Franklin Templeton, have submitted applications for spot XRP ETFs. In fact, ProShares recently requested that the SEC expedite the review of its XRP and Solana ETF proposals, with a decision date now set for June 25, 2025. Franklin Templeton is expected to receive feedback on its XRP ETF application even earlier — on June 17.

This puts XRP in a strong position, especially considering it already has a loyal investor base and active global use cases in remittances and cross-border payments.

Dogecoin, Cardano, and Others Still in the Game

Other well-known altcoins are also in the ETF conversation, though with slightly lower odds. Bloomberg’s analysts estimate that Dogecoin has an 80% chance of ETF approval, while Cardano, Polkadot, HBAR, and Avalanche are each estimated to have a 75% chance of clearing regulatory hurdles.

Newer blockchains like Sui sit further back in the queue, with only a 60% chance of approval, while Tron’s ETF filings are not expected to be seriously considered by the SEC until sometime in 2026.

The probabilities were calculated by analyzing a combination of factors — including whether the SEC has officially acknowledged the ETF application, how likely the crypto asset is to be classified as a commodity, and the deadlines by which the SEC must issue a decision.

Is Solana the Next Big Winner?

Among all the altcoins, Solana seems to have the strongest momentum behind it. Seven different firms have already filed for a spot Solana ETF. With staking products and developer activity surging, many analysts believe Solana is the most likely altcoin to follow Bitcoin and Ethereum into the ETF market.

The SEC could approve Solana ETFs as early as this summer, particularly given how companies like Rex-Osprey are finding legal workarounds to offer staking-based investment products. These strategies are drawing attention from both regulators and investors, and may pave the way for more creative altcoin ETFs in the future.

If Solana gets the green light soon, it could attract significant institutional inflows — especially from investors looking for scalable alternatives to Ethereum.

A New Phase for Crypto in the U.S.

Approval of these altcoin ETFs would mark a significant shift in how U.S. investors access digital assets. ETFs make it easier for traditional investors to gain exposure to crypto without needing to directly hold or manage the underlying tokens. If the SEC approves these funds, it could trigger a wave of institutional adoption across the altcoin sector.

What’s more, the timing of these approvals could play a pivotal role in market momentum. As Bloomberg analyst Eric Balchunas suggested in a recent post, we may be entering a phase where not just Bitcoin and Ethereum, but a full range of high-utility altcoins could become available through ETFs.

What to Watch Next

The key dates to monitor include June 17, when Franklin Templeton could receive word on its XRP ETF, and June 25, when the SEC must decide on ProShares’ Solana and XRP ETF applications. If approvals come through, we could see major price rallies and a broadening of the crypto investment landscape in the U.S.

Investors, traders, and institutions alike are now watching closely. Whether you’re betting on Solana’s speed, XRP’s payment utility, or Litecoin’s longevity, the next few months could reshape how altcoins are integrated into mainstream portfolios.