Help for phrases

[vincent829]

There's motherhood and apple pie. And then there is the pledge by money market funds not to "break the buck"- or allow net asset value to fall below face value, meaning losses for investors.

Bread and butter activities, particularly property and casualty insurance, have produced such good returns recently that reinsurers have not needed to chase yield.
Can some explain the meaning in blue? Thank you.

[vincent829]

help plz

[jamiep]

The first two phrases sound fairly US and I'm not sure about them but "Bread and butter" means the core business activities, what the company does a lot of and should do well.

The origin is that "bread and butter" is a basic food that is easily prepared you shouldn't get wrong.