Bitcoin has the strongest scarcity, known as digital gold, suitable for long-term preservation of value. The total supply of Bitcoin is only 21 million coins, with no further issuance, and mining difficulty halves every 4 years. Currently, only 2 million coins are left unmined. Its cost-effectiveness surpasses gold, as it will take decades to mine all the gold worldwide, but Bitcoin will be fully mined in just 20 years. Its core logic is to counteract fiat currency devaluation, making it the ultimate asset in a global liquidity flood. Institutions and large investors treat it as a ballast asset. The downside is its limited functionality; besides transfers and storage, it can't do much else. But just because of its scarcity, holding it long-term is as stable as an old dog.