Ukraine’s Operation Vivaldi counteroffensive, launched in mid-September 2026 north of Lyman in Donetsk Oblast, has disrupted Russian efforts to encircle the Sloviansk-Kramatorsk defensive positions and produced net territorial losses for Russian forces in September. Independent assessments indicate Ukrainian troops recaptured between 125 and 176 square kilometers, severing logistics routes and forcing Russian redeployments, while Russian gains slowed markedly across the front. Russian forces continue limited offensive operations and infiltration attempts in southern sectors toward key cities, but overall advances remain constrained compared with prior years. These battlefield shifts directly influence trader assessments of timelines for full Russian control over the oblast.