Do Slinkys Defy Gravity?

It turns out that a levitating Slinky has more to do with the speed of sound than gravity. When you hold a Slinky off the ground, the pre-tensioned spring will come to an equilibrium. Just hanging there, the pull of gravity is cancelled out by the tension in the toy.

Why do Slinkies defy gravity?

Held from midair, the Slinky stretches out, quickly reaching a condition known as "equilibrium." in which the downward force of gravity is balanced by the upward tension of the coils above it. When the top is released, the bottom stays suspended. The top of the Slinky collapses, so that the coils slam into each other.

Why does the bottom of a Slinky not move when dropped?

You are absolutely correct that the bottom of the slinky does not move because the tension of the rest of the slinky pulling up balances the force due to gravity pulling down until the moment that the slinky is fully compressed and the whole thing falls with the acceleration due to gravity.