Supply Chain and Predictability of Return

Customer and supplier companies (which form a supply chain) have long-term economic relationships and affect each other. In this study, we answer the question that “whether past returns of the customer (supplier) company can predict the future return of the supplier (customer) company”. To answer this question, we have investigated the predictability of return (or lead-lag relationship) at the industry-level in 10 supply chains of the Tehran Stock Exchange from March 2015 to March 2020 using the vector autoregression model. We found that considerable numbers of supply chains, specifically, 6 out of 10 supply chains in our sample show the lead-lag relationship. In 3 supply chains, customer industry returns lead (or predict) supplier industry returns. Whereas, in the other 3 supply chains, supplier industry returns lead customer industry returns. These observed lead-lag relationships (or predictable returns) across industries provide some evidence of inefficiency in the Tehran Stock Exchange. In addition, we can use these predictable returns to construct profitable trading strategies.