Would you please explain further, especially about that model?

I took a look at the div yield and price history of HYG and they've gone in opposite directions since 2009, so it's followed the same trajectory as govies, although HYG tanked in 09 and its yield peaked in April 09.

Right now HYG price is down and in the past two weeks, yield is up.

How should this all be interpreted? And lastly, is HYG the kind of stand-in you're talking about for lesser quality bonds? And how do we use this information?

tnx