A good friend if mine invests in Biotech companies. Many years ago I asked him about this listed company working on Sonic proteins (yes that's an actual thing) and he replied it's a zombie company. He had looked at acquiring it. Backed off. Several such companies exist especially in Biotech.

It is also a huge phenomonemon in Japan where the Keiretsu also consists of banks and these banks keep kicking the can down the road for all debts for Keiretsu companies. Zombies.