This puzzle is based off the What is a Word™ series started by JLee

If a word satisfies a certain property it is called a Spike Word™. Here are some examples:

Spike Words™,Not Spike Words™
MAGNUM,RAIN
LINK,DEVICE
VANITY,FALLEN
KING,APEX
DUBSTEP,ART
VICTOR,SIMPLE
SICK,FROZEN
MUNCHKIN,HOBBIT
CHRONICLE,ELECTRONIC
VIXEN,HUNTER

What is the rule to tell whether a word is a Spike Word™ or not? Why is it called a Spike Word™? (Note that each word can be tested on its own.)

Technically I should have wrote L1NK and not LINK, S1MPLE and not SIMPLE…