An Etymological Dictionary of the German Language/Stock
Stock, m., ‘stick, staff,’ from MidHG. stoc (ck), OHG. stoc (ch), m., ‘stick, staff, trunk’ (of a tree, &c.); corresponding to Du. stok, AS. stocc, E. stock, OIc. stokkr. The primary meaning ‘stake, club, stick,’ leads to the Sans. root tuj, ‘to brandish or hurl weapons, set in violent motion’ (for Sans. t, equiv. to Teut. st, comp. Stier). From Teut. are derived the Rom. class, Ital. stocco, ‘rapier.’ Allied also to Stück.