The iShares Bitcoin Trust ETF (IBIT), launched on January 11, 2024, has accumulated $46.5 billion in assets under management (AUM) with an expense ratio of 0.25%. In contrast, the Morgan Stanley Bitcoin Trust ETF (MSBT), which launched on April 7, has gathered $392.3 million in AUM and offers a lower expense ratio of 0.14%, making it the cheapest spot Bitcoin ETF. The analysis highlights that while iShares benefits from strong brand recognition and institutional adoption, Morgan Stanley's lower fee could make it a more attractive option for long-term investors, assuming no changes to the expense ratios.