Entity structures: an overview of the options

Education, not tax advice: rules, rates and thresholds change every year, so confirm anything you plan to act on with a qualified tax professional.

Sooner or later every active trader hears "you need an LLC". Sometimes it is true. Often it is a solution to a problem the trader does not have, sold by someone who charges to set it up. This lesson describes the structures, what each one actually changes for tax purposes, and what it costs, so you can evaluate the pitch instead of absorbing it.

The baseline: sole proprietor

Trade in your own name, report on your personal return. If you have trader status, expenses go on Schedule C; gains go on Schedule D or, with a 475 election, Form 4797. Cost: nothing beyond your normal return. This is where most traders start and where many correctly stay.

What it cannot do: it offers no way to pay yourself a salary, so there is no earned income from trading. Without earned income there are no retirement plan contributions from trading profits and no deduction for self-employed health insurance. It also ties the 475 election deadline to April 15.

Single-member LLC

A one-owner LLC is, by default, disregarded for federal tax: the IRS treats it as if it did not exist, and everything is reported exactly as a sole proprietor would. It changes nothing about character, wash sales, 475 or deductions.

What it does change: a new entity can make a 475(f) election within 2 months and 15 days of formation, which is the only route to mid-year mark-to-market treatment. It provides a clean separation between trading and personal accounts, which strengthens the "treated as a business" factor for TTS. It offers some liability separation, though for a trader with no customers or employees the liability being separated is hard to identify.

Costs: state formation and annual fees (some states charge a few dollars, some charge hundreds, and a few charge a flat annual franchise tax in the high hundreds regardless of income), plus a separate brokerage account in the entity's name.

Multi-member LLC or partnership

Two or more owners (often spouses) form an LLC taxed as a partnership. It files its own return (Form 1065) and issues K-1s to the members. The trading business lives in the entity; the members report their shares.

What it changes: the entity can make its own 475 election on its own timeline; expenses are deducted at the entity level; the partnership can pay guaranteed payments to a member, which are treated as earned income and open the door to retirement plan contributions and the health insurance deduction. It also raises the paperwork cost: a partnership return, K-1s, a separate set of books, and higher preparation fees.

S corporation

An LLC or corporation that elects S status files Form 1120-S and pays its owner-employee a W-2 salary. That salary is earned income, which is what unlocks:

• Retirement plan contributions (a solo 401(k) or SEP) funded from trading profits.
• Self-employed health insurance deduction.
• A cleaner separation of business expenses.

Trade-offs: payroll must be run and payroll taxes paid on the salary (Social Security and Medicare, currently 15.3% combined up to the wage base), so the retirement and health deductions are bought with payroll tax. A corporate return, payroll filings and annual state fees add cost. Trading gains that stay in the S corp flow through to the owner as ordinary or capital exactly as before; the entity does not change character.

Illustrative example. A trader with $120,000 of net 475 ordinary income forms an S corp and pays a $40,000 salary. Payroll taxes: $40,000 × 15.3% ≈ $6,120 (half deductible by the corporation). The salary allows, say, a $20,000 solo 401(k) employee deferral plus an employer contribution of 25% of salary ($10,000), $30,000 total, deducted at an illustrative 24% rate: $7,200 of federal tax deferred. Plus health insurance of $8,000 deducted: $1,920. Total benefit about $9,120 against about $6,120 of payroll tax and perhaps $2,000 to $3,000 of extra compliance cost. The numbers are close, and they swing with the trader's income, health premiums, state and appetite for paperwork. This is why no honest source can say "always" or "never".

C corporation

Rarely used for personal trading: entity-level tax plus tax on dividends, and the personal holding company rules can add a penalty tax on undistributed investment income.

Comparison

Things an entity does not do

• It does not create trader status. An LLC that trades 50 times a year is an investor LLC.
• It does not turn short-term gains into long-term gains.
• It does not remove the wash sale rule (only 475 does that).
• It does not shield trading losses from the $3,000 cap (again, only 475 does).
• It does not create Social Security credits unless a salary is paid.

Key idea: Entities change who files and whether a salary can be paid; they do not change what trading income is. The realistic reasons to form one are a mid-year 475 election, retirement and health deductions through earned income, and cleaner business separation, each of which has a cost to weigh.

Try it: Write down three numbers: last year's net trading income, your annual health insurance premium, and the amount you could realistically set aside for retirement. If the second and third are near zero, the S corp column above is mostly cost. If they are large, it is worth a conversation with a professional who can run the actual figures.

Recap

• Sole proprietor is the default and often sufficient; a single-member LLC is disregarded and changes nothing except the option of a mid-year 475 election.
• Partnerships and S corps file their own returns and can create earned income, which unlocks retirement and health deductions at the cost of payroll tax and compliance.
• No entity changes gain character, creates trader status or removes wash sales.
• C corporations are rarely appropriate for personal trading.
• The decision is a cost-benefit calculation on your own numbers, not a rule.