Under the aegis of Federmann the hotel group has continued to grow, thanks to growing tourism and Business in the country as well as ongoing expansion of the chain. Dan Hotels began as a boarding house on the Tel Aviv seafront that was purchased by his Father and uncle in 1947. Over the following decades it grew to be a national chain. It is now expanding into India. Part of the chain is the iconic King David Hotel in Jerusalem, which since its founding in 1932 until this day hosts heads of state and diplomats on behalf of the Israeli government on their visits to Israel.

Federmann joined Elbit when his El-Op company merged with it in 1998. That doubled it in size. Elbit was naturally going to benefit from the global growth of the UAV market however, the 700% growth of Elbit over the following decade was also largely due to Federmann and CEO David Ackerman's leadership of Elbit Systems. They embarked on an ambitious global buyout strategy for the sake of growth. The strategy has made Elbit into a multibillion-dollar multinational.

Since 2002, Federmann has been the owner of Israeli conglomerate Federmann Enterprises Ltd which was started by his late Father and uncle. His cousin Ami Federmann also holds a stake. Federmann chairs the boards of its two biggest publicly traded holdings: defense electronics maker Elbit Systems and luxury hotel operator Dan Hotels Corp.

He was ranked 7th wealthiest in the Maariv newspaper's top 100 in Israel in 2010 with an estimated wealth of 6.5 Billion Shekel (approximately $1.4 Billion). In that year he was ranked No. 721 in the Forbes list of billionaires. In 2011 he was ranked No. 879 and in 2012 he dropped off the ranking of the top 1000.