Find the current 30-days T-bill yield. Will you consider investing in this security given the current market conditions?

Find the most recent (30 days) common equity return for any large company (relatively safe). Compare this return to the performance of treasury with the same maturity. Why common equity is not a money market security? Explain why common equity is not a good choice for short-term investment. (I chose Costco which has a ROE of 26.62%)