The Spring 2016 Quarterly Markets Report prepared by the Internal Market Monitor (IMM) of ISO New England reviews wholesale energy market outcomes for March, April, and May of 2016. The report notes that the total wholesale cost of electricity (including energy, capacity, and ancillary services) during the three-month period was $1.02 billion, down 38% compared to the market value of $1.64 billion during the spring of 2015. The average real-time wholesale energy price was $22.10 per megawatt-hour, a decline of 40% compared to the spring of 2015. The year-over-year decline was driven by lower demand due to milder weather and lower natural gas prices that averaged $2.29 per million British thermal units, 45% lower than the average price during the spring of 2015. The report reviews the performance of Coordinated Transaction Scheduling (CTS), which was implemented December 15, 2015, to improve the efficiency of wholesale power trades between New England and New York. And the report examines the effects of revisions to the regulation market rules since July 2013.