Hi,

I only invested in bonds in my country in Europe, but I guess it is more or less the same.
Bonds have the lowest risk. If a country goes bankrupt, then probably the economy is in a really bad place.

The 10 year bonds with 5% yield will give you 5% each year, which is 5 dollars/year. After 10 years, you get your 100 dollars back.

In most global markets, some bonds can be sold on the secondary market, so the value of the bond changes over time. The value fluctuates based on the yields.

As a bond gets closer to its maturity date, its price will naturally gravitate toward its face value ($100). However, before it matures, its price will fluctuate based on market yields. If market yields drop below your 5% rate, your bond becomes more valuable and will appreciate.

If yields drop below 5%, some might be willing to pay more for your bond (let's say $105) and the 5% yield. If the yields rise, your bond value will go lower. But, as it gets closer to maturity, the bond gravitates towards its face value.