How Many MLPs Are There? Today there are about 90 MLPs, the largest category and the focus of our coverage is energy related MLPs. The number of energy related MLPs total 68 (pro-forma for year-end 2011), with an aggregate market capitalization of approximately $221 billion (see Exhibit 25 on page 23). The median market cap is approximately $1,566 million and the top ten MLPs represent approximately 56.9% of the total (EPD, KMP, WPZ, OKS, PAA, ETP, ETE, EPB, EEP and MMP).