I have a cached dynamic scene I did in Cinema 4D that I've exported out as alembic. I bring it into Houdini as an Alembic scene but unlike in Maya and Cinema 4D it doesn't animate by default. setting the different alembic xforms to $F works fine to get animation going, but in this case I have 30+ objects. Am I doing something wrong here? Is there a way to import Alembics that will have them auto animate?

should work fine by default
if you are using Alembic Archive object to import alembic
and for some reason Frame parm is not set to $FF
set it to $FF and press Push Parameters To Children button to populate it downstream automatically

depending on intended use it may be much more convenient, faster and more flexible to import whole alembic within single Alembic SOP though

Push Parameters To Children did the trick thanks.