Changes > to >= so when both contracts have 0 volume (e.g. off-hours), the further-out standard month wins. Fixes SI resolving to SIJ (April, non-standard) instead of SIK (May, standard delivery month). Also fixes SI/SIL prefix collision by requiring month+digit after symbol. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>