The SEC recently postponed the approval of five cryptocurrency ETFs, and this decision is not particularly surprising. The SEC has always been known for its caution, especially when it comes to volatile assets like altcoins. Their attitude has always been one of careful consideration; ultimately, they are more concerned about the overall stability of the cryptocurrency market and the regulatory framework not keeping pace.

However, if I had to say which ETF is most likely to be approved, I believe it would be one focused on Solana (SOL). Why? First, Solana's technology has developed rapidly in recent years, and its high throughput and low transaction costs have made it stand out in the market, especially in the decentralized finance (DeFi) and NFT sectors where it has strong use cases. Secondly, Solana's ecosystem is continually growing, with an influx of various projects and developers making it more 'reliable' than many other altcoins. Compared to some other cryptocurrencies, Solana's stability and innovation might appeal more to the SEC.