Let's take the following quote from Bloomberg:
Russian government bonds rose, pushing the yield to the lowest level in almost three weeks, as inflation data boosted speculation the central bank may restart interest-rate cuts next year.
Why does the rising price of a bond pushes it's yield down? Because of the bond's risk going lower and bond's bringing back therefore lower returns?
Or take another example, from FT:
The prices of both countries’ bonds plummeted amid fraught negotiations, and yields hit a peak of 48 per cent in Ukraine in April, and 20.47 per cent in Greece in July.
Here we see that risk associated with the bonds in question has skyrocketed, and thus bonds' returns has skyrocketed, too. Am I right?
Now, I assume that bonds' price is determined by the market (issued by a state, traded at the market). Is that correct?
Then who determines bonds' yields? I mean, isn't it fixed? Or - in the FT quote above - they are talking about the yields for the new bonds issued that particular month?