This is a common misconception that stems from Roche’s two-tier capital structure. NVS owns 1/3 of Roche’s voting shares; however, voting shares are only about 20% of Roche’s shares outstanding, so NVS’ equity stake in Roche is about 6%.
“The efficient-market hypothesis may be the foremost piece of B.S. ever promulgated in any area of human knowledge!”