SREI Infra is an infrastructure finance company that provides project financing, equipment financing, and other services. Its business and profitability are closely tied to the macroeconomic cycle and growth in infrastructure spending. The document recommends buying SREI Infra stock as it expects a recovery in the economy to boost infrastructure spending and SREI Infra's earnings. It forecasts SREI Infra's earnings to grow 51% annually from FY14-17 as margins expand due to various factors including lower borrowing costs and improving asset quality.