In the late 1980s, Avdeev started his first business, selling radio components and decoders for TV sets. He was importing computer equipment into Russia, which led to a business with a Ukrainian electronics manufacturer
ElectronMash. In 1994, he bought the
Credit Bank of Moscow. In the 2010s he started to invest into real estate development and construction. Through Rossium, he came into co-ownership of the "36.6" pharmacy chain, founded in 1991 by Artem Bektemirov and Sergey Krivosheyev. Avdeev and the company's CEO, Vladimir Kintsurashvili, have been blamed for the chain's "aggressive" business dealings. In 2013,
Forbes included Avdeev with the net worth of $1.4 billion into the lists of European and global billionaires for the first time. In 2016, he bought OPIN development group from
Mikhail Prokhorov and integrated it into its real estate assets. In 2017, Avdeev became the co-owner of
FC Torpedo Moscow club. ==Assets==