Michael Zenker has a bachelor’s of science in nuclear engineering, but it doesn’t take that kind of smarts to know what’s wrong with the natural gas market: too much gas and too little demand.

Even so, Zenker crunches a lot of numbers as a managing director and the head of natural gas and power research for Barclays in New York City. He looks at production numbers play by play, imports from Canada, how many billions of cubic feet utilities are using, storage, and much more.

He has been watching the ...