为什么买美国国债？这个问题的答案可能涉及到多个方面，下面我们来一一解析。

首先，美国国债作为全球最大的国债市场，其信用等级非常高，违约风险较低。而且，美国国债的利息和收益率也比较稳定，是全球投资者较为青睐的投资品种之一。此外，购买美国国债也可以分散投资风险，因为国债市场的波动性较低，对于追求稳健收益的投资者来说是一个不错的选择。英文翻译为: Why buy US Treasuries? This question may involve multiple reasons, let's analyze them one by one.

Firstly, US Treasuries, as the largest bond market in the world, have a very high credit rating and low default risk. Moreover, the interest rates and yields of US Treasuries are relatively stable, making them one of the more favored investment varieties全球投资者较为青睐的投资品种之一。此外，购买美国国债也可以分散投资风险，因为国债市场的波动性较低，对于追求稳健收益的投资者来说是一个不错的选择。英文翻译为: Why buy US Treasuries? This question may involve multiple reasons, let’s analyze them one by one.