Answer:
- Yes it is.
- Ethical issue ⇒ Insider Trading.
Step-by-step explanation:
Trading on the stock exchange is supposed to be as fair as possible so that every investor has a fair chance of making returns. If a person - like this supervisor - is using information that is material but not publicly disclosed yet to trade on markets, the fairness of the market is compromised because the person will have an edge over other investors which will enable them make unfair profits.
Information on quarterly returns is usually material so we can expect it to be material here as well which means that the supervisor is engaged in insider trading.
Insider trading is not only unethical but also highly illegal. Reporting your supervisor can get them sent to jail.