Ulterior vs. Underlying

Lying beyond what is evident, revealed, or avowed, especially being concealed intentionally so as to deceive

In finance, the underlying of a derivative is an asset, basket of assets, index, or even another derivative, such that the cash flows of the (former) derivative depend on the value of this underlying. There must be an independent way to observe this value to avoid conflicts of interest.

Lying beyond or outside the area of immediate interest.

Lying under or beneath something

Occurring later; subsequent.

Basic; fundamental

Situated beyond, or on the farther side.

Present but not readily noticeable

Beyond what is obvious or evident.

Taking precedence; prior

Being intentionally concealed so as to deceive.

lying underneath

(archaic) Happening later; subsequent.

basic or fundamental

Situated beyond, or on the farther side; thither; - correlative with hither.

implicit

Further; remoter; more distant; succeeding; as, ulterior demands or propositions; ulterior views; what ulterior measures will be adopted is uncertain.

(finance) The entity from whose performance a derivative derives its value.

Ulterior side or part.

present participle of underlie

lying beyond what is openly revealed or avowed (especially being kept in the background or deliberately concealed);

Lying under or beneath; as, the underlying strata of a locality.

beyond or outside an area of immediate interest; remote;

Fundamental; basic; as, underlying principles; underlying causes.

coming at a subsequent time or stage;

Implicit; not immediately obvious; requiring careful scrutiny to discover; as, the underlying sarcasm in her seemingly innocuous remark..

in the nature of something though not readily apparent;

located beneath or below

being or involving basic facts or principles;