Nordic basically buys bankrupt companies IPs. Nordic also bought JoWood when it went bankrupt which is how they got Gothic, The Guild, Painkiller, Broken Sword, etc. They've also picked up Desperados, Jagged Alliance, Delta Force by buying various bankrupt parts of Atari, NovaLogic, etc.
When they had the THQ auction they split out all the stuff people wanted like Relic, Saints Row/Volition, etc. that Sega and everybody else bid on. Then they had a second auction with everything else THQ had, that's what Nordic swept in and bought. They got something like 150 THQ IPs, and the THQ brand name, for $5 million. Along with Rainbow Studios.
As Crytek fell apart, Deep Silver/Koch Media bought the old THQ pieces off of them. Then this year THQ Nordic bought Koch Media.
Nordic was started by a Swedish dude to buy and sell used software, games and comic books. He sold it for $10 million or something during the dotcom boom and then bought it back from the bankrupt company for like $1 after the dotcom crash.