Undermined this business the beginning of the tax maneuver in the oil industry. He was supposed to push the Russian oil refineries to modernize capacity. The Afipsky plant was planning to invest RUB 341 billion in the project, but funding was lagging behind the schedules. Kogan began to look for a buyer for the asset, and in 2019 the plant was bought by Mikhail Gutseriev (Forbes, citing sources, writes that the Kogan family received $ 20 million from the deal, but the new owner got the refinery’s debts - $ 1.8 billion).
Kogan was married, he left four children. In an interview with Kommersant in 2016, he said that when “his comrade” German Gref noticed that returning to the banking market is a risky operation, he did not consider it a risk - including because he has “two senior sons. "