Roleset underlie.01 Verbnet Class: 1 "act as the foundation for":

Roles:

Arg0:thing acting as a foundation


Arg1:foundation for what?

Examples:

typical usage (-)
Speculation, on the other hand, sparked buying in certain incentive-backed issues, though rumors underlying such shares eventually proved untrue.
Arg0:	rumors
REL:	underlying
Arg1:	such shares

Ignore adjectival usages like "the underlying causes of the recession."