Is it ok to write about something not on my college resume?

Hi,
For my college essay, I was wondering whether it would be ok to write about something that I didn’t list on my activities list. Specifically, I am very interested in the stock market, and I am considering writing about this interest in my essay, however, I have no extracurricular activities that are remotely related to the stock market. Would colleges look down upon my essay if I were to write about the stock market anyways?

I read about someone who was accepted into U Penn by writing about baking and how relaxing it was. You can write about anything.

They want to learn something about you that they don’t know already, so something that’s not on your activities list is going to give your application a much more well-rounded feel. Unless you have something in your activities list that’s kind of weird and you feel it needs some more explaining, then I think it would be a good idea to write about something you didn’t mention.

It is fine to write about something not on your app. But be sure the topic is revealing something about your personality and what makes you tick, and gives them reasons to want you on campus. An essay I your interest I the stock market could go either way…

Which prompt would this address?

I guess this is my question: if this interest is so strong that it’s worth writing about, why isn’t it reflected anywhere else on your application? Not in the classes you’ve taken, not in any extra curricular activities, not in what you did over the summer?