Not all that different from shares in a private company, or an interest in a partnership or multi-member LLC. Many corporate shareholders cannot freely sell; the idea of being able to sell stock for cash whenever you want to is unique to public companies.
And yes, the real problem is information asymmetry. This is always the real problem. Arguably the secretary who knows everything that's going on with the company via watercooler talk has more power than the CEO whose underlings tell him only what he wants to hear. A lot of corporate owners, even powerful shareholders like the Crown Prince of Saudi Arabia, have been bilked by unscrupulous but savvy management who knows how to control information flow.
And yes, the real problem is information asymmetry. This is always the real problem. Arguably the secretary who knows everything that's going on with the company via watercooler talk has more power than the CEO whose underlings tell him only what he wants to hear. A lot of corporate owners, even powerful shareholders like the Crown Prince of Saudi Arabia, have been bilked by unscrupulous but savvy management who knows how to control information flow.