Accounting firms also limit the trading and financial accounts senior employees can hold and require all financial assets to be recorded in a database for compliance monitoring. Because they audit many companies, employees are also required to close certain financial accounts and even sell stocks in firms they audit, often at a financial cost to employees (taxes, lost opportunities) that they do not reimburse. It sucks.
Some Top Strategy Firms hold retirement assets for employees in a sort of blind trust, where employees cant know where assets are invested, other than as a category of investment (eg hedge fund, us stock index, bonds, etc.). The management fees for this structure drags earnings a bit, which also sucks, but it is required.
On the plus side, these policies tend to limit speculation and market timing by employees and employer contributions tend to be fairly generous.