They are bonds. Unless they default they will eventually reach maturity and pay out the original gain. The problem is that might be a 20% gain 10 years from no

They are bonds. Unless they default they will eventually reach maturity and pay out the original gain. The problem is that might be a 20% gain 10 years from now, so nobody will be willing to buy that bond off of you for the price you paid since they can 40% on new 10 year bonds. The only time a bond price decline is concerning is if you have to sell it rather than holding to maturity.