I am thinking of setting up a single member LLC that only does trading (stocks) and doesn’t have any other activities, it is taxed as passthrough. I can’t seem to find a clear cut answer to some of my questions.

Trying to figure out if it is worth trading stocks through an LLC vs without one. I know the brokers charge you for professional real time quotes if you are an LLC but is there any advantage that outweighs that cost? Primarily:

  1. Do I have to pay self employment tax for the capital gains?

  2. Can I contribute to a SEP plan?

  3. Does the LLC qualify for the 20% QBI deduction?

  4. Can I write off business expenses (e.g. traveling to a conference on investing, buying books on the topic or attending classes)

I appreciate your input.

Thank you