LIQUIDITY
Have you ever experienced thirst, approached the glass, picked up the pitcher of water, and when you tilt it to fill the glass, not enough water comes out?
It happens that upon checking what the problem is, you find that the lid is in the closed position, which causes the phenomenon of "low liquidity". :) The same can occur in the Market if many asset holders keep them in their wallets, and few offer them on Exchanges. This situation can even occur with instruments of good Market Capitalization.
Therefore, liquidity is very important to maintain the vitality of any asset. If there are offers and no buyers, downward trends arise. And if there is demand, and no sellers, upward trends arise. The Market provides the channel to bring about a balance in harmony between buyers and sellers. The more active and numerous the volume of any instrument, the better signal of liquidity it will represent.
Holders can sell and investors can buy.