We study how firms‘ use of big data shapes the transmission of macroeconomic shocks to investment. Using employer-employee data on job characteristics to measure firm-level data intensity, we show that data-intensive firms respond more strongly to monetary policy shocks. The relationship between data intensity and investment cyclicality is non-linear: it is negative among firms in the lower four quintiles of the data intensity distribution but significantly attenuated among the most data-intensive firms. We develop a theoretical model with endogenous data acquisition to explain these findings. Data raises expected productivity and lowers uncertainty, reducing firms’ investment costs. Because capital and data acquisition are strategic complements, aggregate shocks induce adjustments in data acquisition that amplify investment responses, especially for data-rich firms. Our results imply that changes in firms‘ access to data ― potentially driven by digital markets regulation ― can meaningfully affect both the potency of monetary transmission and business cycle fluctuations.