I'm not a financial expert, but I stick to target date funds and S&P 500 index funds. I never try to pick individual stocks.
Something I don't quite understand is how a company like Amgen can be valued so low, then get bought out at a premium, and suddenly Pfizer's value increases. Shouldn't Amgen have been valued higher to begin with if its prospects were so good? When Pfizer buys Amgen does Pfizer immediately increase in value? I know combining with a larger company can help with trials, marketing, and production, but the initial valuation still confuses me. I follow Jack Bogle's investment advice; he made index funds accessible to everyone, creating Vanguard Group.
Also, I'm curious why Pfizer halted its Phase 3 trial for a weight loss drug due to slightly elevated liver enzymes in just one person. I think that there must have been more concerns than just that one individual; perhaps more serious liver damage or other bad side effects? Just my thoughts.