scalper vs plunger

scalper and plunger both are nouns.

Word	Noun	Adjective	Verb	Adverb
scalper	Yes	No	No	No
plunger	Yes	No	No	No

As nouns, plunger is a hypernym of scalper; that is, plunger is a word with a broader meaning than scalper:

scalper: someone who buys something and resells it at a price far above the initial cost
plunger: someone who risks losses for the possibility of considerable gains

Other hypernyms of scalper include speculator.

scalper (noun)	plunger (noun)
someone who buys something and resells it at a price far above the initial cost	mechanical device that has a plunging or thrusting motion
	hand tool consisting of a stick with a rubber suction cup at one end; used to clean clogged drains
	someone who risks losses for the possibility of considerable gains
	someone who dives (into water)