GRESB is a collaborative ESG data platform that assesses and benchmarks the sustainability performance of real assets including real estate portfolios. In 2018, GRESB assessed 903 entities across 64 countries representing 79,000 assets valued at $3.5 trillion. GRESB provides investors with an aggregated view of the sustainability of their portfolios to inform engagement and decision making. Participants receive benchmarking and analytics to identify opportunities to improve sustainability performance and business practices. Listed real estate portfolios continue to outperform private real estate portfolios in overall sustainability scores according to GRESB's 2018 results.