Let's think of this a different way . . .
In my example, a European investor who was looking to earn $400 in U.S. dollars was willing to pay $10,000 (in its Euro equivalent) five years ago to get that return. Today, he's only willing to pay $6,500 to get that same return. His "coupon" is still the same in both cases (4%), but the price (in his own currency) that he's willing to pay for that coupon is 35% lower today than it was five years ago.
As far as currency fluctuations, if I knew that, I'd be worth $1 billion, at least.
Not necessarily. And I think you're smarter than that.
If the U.S. government were a publicly-traded corporation, any smart investor would look at its balance sheet and determine that there are some serious bumps in the road ahead. THAT is why the dollar has been in such a steep decline. An investor can demand a higher dividend, pay a lower price for the company stock, or both. Right now Uncle Sam is paying a fixed "dividend" . . . so prospective investors have simply bid down the price of the "stock."
Yes, he lost $3500 since he bought the bond. He's still earning 4%. If he wanted to earn more, he should sell now.
Right now Uncle Sam is paying a fixed "dividend"
New bonds go on sale all the time. And the coupon is still low. For now.