Abstract: I will finish the presentation, initiated in the previous seminar, on Furstenberg's theory for the top Lyapunov exponent of products of i.i.d. random matrices. The material presented is based on the papers: H. Furstenberg, Noncommuting random products, Trans. Amer. Math. Soc. 108 (1963) 366-428, and H. Furstenberg & Y. Kifer, Random matrix products and measures on projective spaces, Israel J. of Math. 46 (1983) 12-32.