Good article on the subject in the NY Times.
Also saw this in a weekly email I get from an MIT trained financial advisor
" This story highlights a key challenge for investors: On the one hand, picking stocks can sometimes be as easy as it looks. That was the case initially with Novo Nordisk. When Ozempic hit the market, it was clear the company had a winning formula. Patients were routinely losing as much as 20% of their body weight. Sure enough, positive financial results followed. An investor who chose to bet on this trend would have been right.
But if stock-picking can be this straightforward, why does it often turn out to be so hard? Decades of data tell us that it’s enormously difficult, even for professional fund managers, to beat the market. Why is that?
Recent research sheds light on this question. In a study of more than 20,000 mutual funds over a 35-year period, researchers found that fund managers actually do a reasonably good job at picking stocks. But that turns out to be only half the battle. When it comes to timing decisions, fund managers struggle. In nearly every geography and every time period, timing decisions subtracted value. Stock-pickers, in other words, are good at picking stocks but not very good at deciding when to buy or sell them. A closer look at Novo’s recent history can help us see why this is often such a challenge.
For Novo Nordisk—despite its early success with Wegovy—everything seemed to go wrong at the same time.
Research paper cited is “Mutual Fund Skill”
intercst