As pension saving managers, pension funds are able to finance long term investment, R&D and innovation while assuring their role as traditional institutional investors (activism, outsourcing of internal management bias...). As such pension funds can play a crucial role in the French investment dynamic which is mostly characterized by the use of credit. However, among the studies on the influence of institutional investors, few are those specifically interested in pension funds, and none focuses on the French case. This article aims to fill this gap in the literature by studying the impact of pension fund investments of CAC 40 firms' performance. Our results, over the period 2004-2016, highlight a negative influence of pension funds' participation. We explain those findings by the weakness of pension funds' participation and their foreign origin.