Although there are many examples throughout history of positive changes in top company management teams, important personnel moves tend to unsettle investors. They get worried that significant changes could reflect instability, indecision, or both in a company's decision-making. That seemed to be very much the case Monday with biotech Scholar Rock (SRRK -3.35%). Its stock closed almost 4% lower in price on a day when the S&P 500 index basically traded flat. A quartet of new executive appointments Scholar Ro ...