Preferred Stock ETF

See: Exchange-Traded Fund (ETF).

It's just an ETF filled with shares of preferred stock.

Preferred stock acts like a bond (it just sits there, boringly paying interest) and doesn't grow. But because it's usually convertible into common stock, it's classified as equity, not debt, i.e. the issuer isn't obligated to retire the preferred. So an ETF filled with this stuff will be whipped around with bond rates; when rates go up, the value of that ETF goes down, and vice versa. So yeah...there's an inverse relationship between bond prices and yield.