CME Group /zigman2/quotes/210449693/composite CME +1.74% says it has been testing negative trades for oil futures, of major energy prices fall below zero. "CME Clearing has a tested plan to support the possibility of a negative options underlying and enable markets to continue to function normally," the exchange operator said in a note on April 8 . CME reiterated on Monday that if West Texas Intermediate oil futures, in any month, settle at a price between $8 and $11 a barrel that it could switch to a price model that would allow for negative pricing. On Monday, the WTI contract for May delivery traded on the New York Mercantile Exchange /zigman2/quotes/211629951/delayed CL.1 -0.67% , which expires on Tuesday, was down $19.70, or more than 100%, at negative $1.43 cents a barrel. The June contract , which is the most actively traded, was down $3.47, or 14%, at $21.52 a barrel.