the.com/stockholder

means A person or entity that owns shares of stock in a corporation, giving them a fractional claim on its profits and assets.

from From 'stock' in its old sense of a trading company's pooled capital — the word 'stock' itself traces back to the trunk of a tree, the solid base from which something grows — combined with 'holder,' one who possesses. By the 1600s English trading companies issued shares of this 'joint stock,' and whoever held a piece of it, held a stake in the venture itself.