كَمْ: declarative, indeclinable on sukūn, at the beginning of the clause.
مَالٍ: singular genitive tamyīz.
أَنْفَقْتُ: past verb; tāʾ is the subject.
هُ: accusative object pronoun referring to the wealth.
Since the verb already takes the resumptive object pronoun hu, kam is analysed as a nominative-position topic, and the verb clause is its predicate.