The objective of this work is to identify the nature of the relationship between the profitability of the two financial assets belonging to the Paris stock exchange, our study showed its performance thanks to the results found, the performance indicator of the Paris stock exchange, has a relationship with the shares that compose it, particularly with the share of the company DANONE that it has a share of 2. 76%, according to statistics, it has been shown that the Danone share is strongly linked to the CAC40 stock market index, so that each change of one unit in the profitability of the CAC40 index influences the profitability of the Danone share by 25%, in addition to this, the two variables follow a normal law, whose points are perfectly distributed in the form of a bell author of the average, it is also observed that the distribution of these points is between -5% and +5%, i.e. fluctuations in the share's profitability cannot exceed 5% upwards or downwards.The CAC40 has a positive and significant effect at the 5% threshold on the DANONE share's profitability.