Unless you are not taking out any student loans whatsoever, I would advise against putting any of your money into stocks or bonds, or writing or buying options while in medical school. If you're investing intelligently, you are looking to make reasonable gains over a long period of time, and then reinvest those. You will almost assuredly lose more money to interest in student loans than you will make on investments in the market over a period of 4 years. This is why every guide ever written on "how should I start to invest" says the #1 and #2 things you do are set up an emergency fund, and pay off debt. People don't realize that paying off debt (or, in our case, taking out less debt) is a great investment. Your return on investment is typically higher (~7% for student loans, much higher for credit card debt), and, more importantly, there is no risk involved.
If you were thinking of using the market as a primary income-generating strategy and you are under 50 and don't have a strong dividend portfolio, you're approaching it the wrong way.