This paper aims to improve GNSS signal processing for collaborating receivers through the development of a Cooperative Vector Delay/Frequency Lock Loop (CVDFLL), a variant of the conventional Vector Delay/Frequency Lock Loop (VDFLL) utilized in standalone receivers. The VDFLL enhances signal processing by taking advantage of spatial correlation between navigation satellites. The CVDFLL expands this advantage to spatial correlation between receivers of similar user dynamics. The algorithm relies on the pseudorange-state formulation of the VDFLL for collaborative processing as a means to keep the cooperative network federated. Additionally, this formulation is expected to be less sensitive to dissimilar dynamics between receivers. Monte-Carlo simulation and experimental results show that cooperative vector tracking can be very robust when employing several receivers. However, the analysis also suggests that the CVDFLL should be studied with a position-state formulation of the VDFLL due to its robust nature as well as the generally poor performance of the pseudorange-state filter.