I believe you can file LLC return the same way as a multi-member LLC, like a S-corp or partnership. This is why LLC is so flexible.
that is naive to think.... a solo LLC can be easily pierce given it is easy to prove that it is the alterego of the individual... consult an attorney if your concern is liability, a combination of LLC and umbrella/E&O might cover you, but if you are trading under an LLC (an make tons of $$$) your concern is shielding those assets from external liabilities not generated by the business but rather you... meaning, you hit someone in an accident, they sue you and come after you and anything you control for satisfying the judgement...
Multi-member LLC trading business are better off filing a partnership tax return, rather than making an S-Corp election. The partnership tax return has more flexibility over an S-Corp return. The partnership can pay an admin fee, whereas the IRS prefers officer's salaries in the S-Corp. The partnership can have "UPE" unreimbursed partnership expenses, whereas the S-Corp should do reimbursements before year end. It's not convenient doing reimbursements before year end and the partnership doesn't have that worry, just listing the UPE on the individual return Schedule E. But, for a single person, the S-Corp is a good choice.
Investment management (IM) is entirely different from trader tax status (TTS). IM net income on a Schedule C is earned income subject to SE tax. IM businesses consider S-corp elections to reduce SE tax by 50% to 75%. We cover this in our content. There aren't different options here, the rules are clear, either you do it right or wrong. Some accountants don't understand trader tax status and do it wrong.