This paper examines how investment and input-output networks interact in transmitting U.S. monetary policy shocks to sectoral stock returns. We develop a theoretical multisector model featuring an adjusted-investment network, capturing investment-linkage transmission amplified by input-output linkages. Using a heterogeneous panel spatial autoregressive model with orthogonalized monetary policy shocks, we find that the adjusted-investment network accounts for 38% of the total stock-return response. Moreover, indirect spillovers through adjusted-investment linkages account for 33% of the total effect, comparable to 41% through input-output linkages. Therefore, the interplay between the two networks is an important channel of monetary transmission.