Since the split with COP, Phillips has done quite well. If you take the shares received and kept them along with COP, your original investment is now worth $107.75 per share of pre split COP. Looks like this was a good move for the stockholders. the dividend is pretty healthy too. Glad I held all my proceeds from the split.
Part of the problem with the old company is that it was not run very well. Companies do not generally sell off Billions upon billions of dollars of mineral rights. They had more property than they could have ever developed and some of it was sub par. Cop is still trying to get the portfolio right. This was not the fault of just COP but many of the other big integrated companies.
Wall street let these guys get away with a lot for a long time. The PSX part was hidden in the gigantic E&P part. PSX has some really great properties. I started buying into this company when the spin off rumor started and they got serious about dumping the excess baggage. After the split I kept the E&P and bought more of PSX.