/stɒk/
[noun] A supply of goods or materials kept ready for use or sale; also a share of ownership in a company. The word has many meanings, but most of them connect to the idea of something solid that other things grow from or depend on.
The financial 'stock' you buy in companies started life as a literal tree trunk — the solid, rooted base everything else grows from.
Few English words have lived as many lives as 'stock.' Its oldest ancestor is the Old English word 'stocc,' meaning a tree trunk, a post, or a block of wood — something solid, immovable, and rooted in the earth. This word descended from the Proto-Germanic root *stukkaz, which also gave rise to Old High German 'stoc' and Old Norse 'stokkr,' both meaning a tree trunk or log. The image at the heart of all these words is simple and physical: a thick, cut piece of wood standing upright in the ground.
From that concrete starting point, the word began to branch outward — much like the tree itself. In the medieval period, 'stock' came to mean the main stem or trunk of a family line, the root from which all the descendants grew. A person's 'stock' was their ancestry, their lineage, their blood. This is why we still say someone comes from 'good stock,' meaning their family background is strong or respectable. The metaphor was natural and vivid to people who lived close to the land: just as a healthy trunk produces strong branches, a good family line produces capable descendants.
By the late medieval period, English merchants and craftsmen had extended the word further. A 'stock' of goods was the supply kept on hand — the ready store from which things could be drawn as needed. The idea was of something accumulated, something solid and available, like a pile of cut wood waiting to be used. This mercantile sense gave rise to 'livestock' (the animals a farmer keeps), 'stockpile,' and 'stock-in-trade.' When we say a shop has something 'in stock,' we are using a meaning that was already well established by the 15th century.
The financial sense — a share of ownership in a company — arrived in the 17th century and is perhaps the most surprising turn of all. When early joint-stock companies needed a way to describe the collective fund that investors contributed, they reached for 'stock' as the image of a central, shared trunk from which profits could grow and be distributed. The word moved from wood to wealth with remarkable ease. The London Stock Exchange, founded in 1801, made this usage permanent in the global financial vocabulary.
Beyond commerce and finance, 'stock' also gave us the rich broth made by boiling bones and vegetables — the liquid 'base' or foundation of a soup, again echoing that original sense of a solid, supportive trunk. And in the phrase 'stock still,' meaning completely motionless, we hear the oldest meaning of all: as still and fixed as a post driven into the ground. Even 'laughingstock' carries the original wooden image — it referred to a post to which a person was tied for public mockery, the stocks of punishment. Every branch of this word, however far it reaches, can be traced back to that single rooted trunk.