Who’s buying the 30yr note tomorrow

4.25% coupon - For 25k you’ll get a little over 1k a year in recurring income. For someone wanting to bump up their fixed income portfolio what’s the downside? I haven’t bought such long term but when I thought about doubling my money in 25 years it doesn’t sound bad. If I need the money back earlier I’d think rates will drop in the future so could sell at a gain (others are welcome to challenge this)