So in my opinion HP is a peculiar case and is neither. The first reason being it can't be a Monopoly because the FTC would've already blocked them. And they are too weak to be a oligopoly, but they could be in an oligopoly industry( I can go both ways on this). Tbh it is hard to explain since they split into two separate entities in 2015. I was thinking they could be a conglomerate such as JNJ, PG or Coca Cola. But being the mediocre company they are they don't have any subsidiaries, at least major ones. Their market is shared by Toshiba, Canon, Dell, Lenovo, IBM, Cisco, Acer and Brother among some. Now obviously this industry is tightly packed, the printer market share is probably the closest HP can get to superiority but Canon and Brother printers are right behind. PC/Laptop industry is ruled by Lenovo, Acer and Dell. Unless in an office setting I cant see HP competing in the consumer market. In all, I just don't see HP as an oligopoly cause they are outnumbered in the industry, and the FTC would block them being a monopoly ( which they aren't or else they would have something going for them).