In the progress of cryptocurrency ETFs, the U.S. SEC has once again surprised the market. Just a day after approving Grayscale's conversion of a fund to an ETF, it urgently halted another conversion plan the next day, stating that further review is needed. This not only affects market nerves but also puts the ETF proposals for other assets, including SOL, XRP, and DOGE, into uncertainty. Currently, the SEC is adopting a 'case-by-case review' strategy for multiple cryptocurrency ETFs, and some have even entered a fast-track review phase, indicating that while there are signs of a loosening regulatory attitude, there remains a clear vigilance. The market is closely watching whether more funds will successfully pass the review and officially enter the mainstream trading market.