A prop account LLC is a limited liability company you form to trade your own capital, and its tax value comes not from the entity itself but from qualifying for Trader Tax Status and making the Section 475(f) mark-to-market election on time. The LLC is the legal shell. The savings live in the elections you attach to it.
Set up the entity without those elections and you have an expensive brokerage account wrapper. Set it up correctly and you unlock business expense deductions, unlimited ordinary loss treatment on trading losses, exemption from wash sale rules, and, in some cases, self-employment tax planning through an S-Corp election.
What the LLC Does and Doesn’t Do
“Proprietary” in this context just means you’re trading your own money through a business entity rather than a personal account. The LLC becomes the legal owner of the brokerage account, the equipment, and the associated expenses. It provides liability separation and a professional framework.
What it does not do is automatically create any tax benefit. An LLC that holds a brokerage account but fails to meet the IRS definition of a trade or business is taxed the same as a personal account. Three things have to work together: the LLC for the structure, Trader Tax Status to qualify the activity as a business, and specific elections to shape how gains and losses are treated.
Forming the Entity
File Articles of Organization with the Secretary of State in your home state. Forming at home is almost always the practical choice because forming elsewhere means registering as a foreign entity in your home state anyway. Filing fees vary but most fall between $50 and $150.
Draft an Operating Agreement even as a solo member. It defines capital contributions, management authority, and profit and loss allocations. Courts look at this document when deciding whether the LLC is genuinely separate from you, and a missing or sloppy agreement weakens the liability shield you formed the entity to get.
After the state filing is complete, apply for an Employer Identification Number from the IRS. The IRS requires the state formation to happen first, so don’t jump ahead.1Internal Revenue Service. Get an Employer Identification Number The EIN is needed to open a business bank account and to make tax elections later.
Open a dedicated business bank account, fund it with your capital contribution, and route every trading-related transaction through it. Mixing personal and business funds is the fastest way to lose your liability protection.
Many states also require annual reports or franchise tax payments. These ongoing fees range from nothing in some states to $800 or more annually in others. Missing an annual filing can trigger administrative dissolution, so build the deadline into your calendar from day one.
Qualifying for Trader Tax Status
Trader Tax Status is not a box you check. It’s a factual determination based on how you actually trade. Without it, your LLC is treated as holding investments, and the business expense deductions and mark-to-market election are off the table.
The IRS requires three things: you must seek to profit from daily market price movements rather than dividends or long-term appreciation, your trading activity must be substantial, and you must carry on the activity with continuity and regularity. Courts evaluate four specific factors: typical holding periods, frequency and dollar amount of trades, how much income the activity produces relative to your livelihood, and time devoted to it.2Internal Revenue Service. Topic No. 429, Traders in Securities
There is no bright-line test. Some practitioners cite 720 or more trades per year with average holding periods under 31 days, but the IRS has never published those specific numbers. In Chen v. Commissioner, the court found that 303 trades over three months was insufficient when the trader had no activity during the remaining six months of the year. In Nelson v. Commissioner, the court denied TTS where the taxpayer had eight stretches of seven or more consecutive days with no trading at all. Pattern matters as much as raw count.
What consistently wins in court: trading nearly every market day, holding positions for days rather than months, spending several hours daily on research and execution, and generating enough volume that the activity looks like a full-time occupation. If you have significant outside employment income and trade sporadically, you’re an investor in the IRS’s view regardless of your LLC.
What TTS Gives You
A qualified trader deducts ordinary and necessary business expenses directly against income on Schedule C.2Internal Revenue Service. Topic No. 429, Traders in Securities These include trading platform subscriptions, real-time data feeds, computer equipment, professional tax preparation, and home office expenses calculated on Form 8829.3Internal Revenue Service. Instructions for Form 8829 Monitors, computers, and networking hardware can be expensed immediately under Section 179, which allows up to $2,560,000 in deductions for 2026. Off-the-shelf trading software qualifies as well.4Internal Revenue Service. Publication 946, How To Depreciate Property
An investor gets none of that. Investment-related expenses fall under miscellaneous itemized deductions, which the Tax Cuts and Jobs Act suspended starting in 2018 and the One Big Beautiful Bill Act permanently eliminated beginning in 2026. Investors cannot deduct these expenses at all.
Keeping Records That Hold Up
The burden of proof in an audit is on you. Keep a daily trading log recording start and stop times, number of trades executed, research activities, and the strategy behind your positions. Brokerage statements confirm the trades. Only your own records show the time and effort. Traders who lose in tax court almost always fail on documentation, not on actual volume.
The Mark-to-Market Election
Section 475(f) is the single most valuable tax tool available to a qualified trader, and it’s only available if you have TTS. It changes how the IRS treats your gains and losses.
How It Changes the Math
Without MTM, trading losses are capital losses. You can only deduct them against capital gains, plus up to $3,000 per year against ordinary income, with anything beyond that carried forward indefinitely.5Office of the Law Revision Counsel. 26 U.S. Code 1211 – Limitation on Capital Losses A trader who loses $80,000 in a bad year with no capital gains would need over 25 years to fully deduct that loss.
With MTM, all net trading losses become ordinary business losses with no annual cap. That $80,000 loss offsets your full ordinary income in the year it occurs, including a spouse’s wages on a joint return.2Internal Revenue Service. Topic No. 429, Traders in Securities The election also exempts you from wash sale rules. For active traders making dozens of trades daily in the same securities, wash sale adjustments can create phantom taxable gains that don’t reflect actual economic results, so the exemption is a major practical benefit.
MTM also simplifies year-end reporting. Positions held on December 31 are treated as sold at fair market value on the last business day of the year. You don’t track individual lot costs or specific identification of shares.
What You Give Up
Every MTM gain is taxed as ordinary income regardless of holding period. You permanently give up preferential long-term capital gains treatment, which tops out at 20% for most high earners. If your strategy involves holding some positions longer than a year, MTM could cost more than it saves. The election fits traders who rarely hold beyond a few days, where long-term rates were never going to apply anyway.
Deadlines That Cannot Be Extended
The timing is unforgiving, and this is where most traders who want MTM stumble.
An existing taxpayer must file the election statement by the original due date, without extensions, of the return for the year before the election takes effect. If you want MTM for 2027, the statement must be attached to your 2026 return, or to a timely extension request, filed by April 15, 2027. The statement must identify the election under Section 475(f), the first tax year it applies to, and the specific trade or business.2Internal Revenue Service. Topic No. 429, Traders in Securities
A new taxpayer who wasn’t required to file a return for the prior year gets a different window. Place the election statement in your books and records no later than two months and 15 days after the first day of the election year, then attach a copy to your return for that year.2Internal Revenue Service. Topic No. 429, Traders in Securities This is a real advantage of forming a new LLC. A brand-new entity that begins trading on January 1 has until March 17 to make the election for that same year, skipping the usual requirement to wait a year.
The election is effectively permanent. Revocation requires IRS permission, which is rarely granted. Think carefully before electing.
Choosing How the LLC Is Taxed
The LLC is a check-the-box entity. You choose how the IRS taxes it. The default depends on member count, but a different classification may reduce your overall burden.
The Default
A single-member LLC defaults to a disregarded entity, taxed like a sole proprietorship. Income and expenses flow onto your personal return via Schedule C.6Internal Revenue Service. Entities 3 A multi-member LLC defaults to partnership taxation, filing Form 1065 and issuing each member a Schedule K-1.7Internal Revenue Service. LLC Filing as a Corporation or Partnership
For many TTS traders the default single-member structure works fine. Business expenses go on Schedule C, and trading gains and losses go on Schedule D, or on Form 4797 with the MTM election. Simple structure, low compliance cost.
Electing S-Corp Status
An LLC can elect S-Corporation taxation by filing Form 2553. A new LLC must file within 75 days of formation to have the election apply to its first tax year. The S-Corp is a pass-through entity, so income still flows to your personal return, but employment tax treatment changes.8Internal Revenue Service. S Corporations
In a standard S-Corp, the owner-employee splits compensation between a reasonable salary subject to payroll taxes and distributions that avoid those taxes. Self-employment tax runs 15.3%, covering 12.4% for Social Security on earnings up to $184,500 in 2026 and 2.9% for Medicare on all earnings.9Internal Revenue Service. Self-Employment Tax (Social Security and Medicare Taxes)
For traders specifically, whether the underlying gains are subject to SE tax at all is the threshold question. Without MTM, trading gains are capital gains on Schedule D, and capital gains are generally excluded from SE tax. With MTM, gains become ordinary income, and whether that income is subject to SE tax is a genuinely unsettled question among practitioners. Some argue MTM gains from a trade or business are net earnings from self-employment; others hold that the character of trading gains exempts them regardless of the election.
The practical takeaway: S-Corp SE savings are not automatic. You need a tax professional who works with traders to model your situation. Where the election clearly adds value is when you have significant income subject to SE tax and the salary-versus-distribution split is worth the added compliance.
If you do elect S-Corp status, the salary must be reasonable. The IRS looks at training and experience, time devoted to the business, comparable pay for similar roles, and the salary-to-distribution ratio.10Internal Revenue Service. S Corporation Employees, Shareholders and Corporate Officers Setting salary artificially low and taking most income as distributions is the exact pattern the IRS challenges. In Watson v. United States, the court rejected a shareholder’s $24,000 salary when the business generated far more, holding that the taxpayer’s intent to limit wages is not a controlling factor.
C-Corp Is Usually the Wrong Fit
An LLC can elect C-Corporation taxation by filing Form 8832. C-Corp profits face a flat 21% federal rate.7Internal Revenue Service. LLC Filing as a Corporation or Partnership The catch is double taxation: the corporation pays, then you pay again on distributions. For most prop traders, pass-through structures make more sense. C-Corp is worth considering only if you plan to retain significant earnings in the entity at 21% rather than distribute them, or if you want access to fringe benefits only corporate employees receive tax-free.
Costs and Reporting to Plan For
One expense that catches new trading LLCs off guard is the reclassification of market data. Exchanges like CME Group classify data subscribers as professional or non-professional, and trading through a business entity almost always triggers professional status.
The price gap is dramatic. CME Group’s January 2026 fee schedule charges non-professional subscribers as little as $4.65 per month for a bundled top-of-book package across all four exchanges. Professionals pay $134.50 per month for a single display device with real-time data. E-Mini data packages for professionals range from $42.25 to $73.00 per exchange per month.11CME Group. January 2026 Market Data Fee List Similar reclassifications apply across NYSE, Nasdaq, and other exchanges. These fees are fully deductible under TTS, but budget for them before forming the entity because the increase hits as soon as your brokerage account is registered to the LLC.
If your LLC holds capital in foreign brokerage accounts or trades through a foreign platform, two separate reports may apply. Under FATCA, Form 8938 is required when the total value of foreign financial assets exceeds $50,000 on the last day of the tax year or $75,000 at any time during the year for unmarried filers, with thresholds doubling for married couples filing jointly. Separately, FinCEN Form 114 (the FBAR) is required for any U.S. person with a financial interest in or signature authority over foreign financial accounts exceeding $10,000 in aggregate at any point during the year. Filing Form 8938 does not satisfy the FBAR requirement; both must be filed independently.12Internal Revenue Service. Summary of FATCA Reporting for U.S. Taxpayers FBAR penalties can reach $10,000 or more per violation even for non-willful failures.
Sequence and Timing
Order matters, because several deadlines run from the formation date and cannot be extended.
- File Articles of Organization. This establishes the LLC and starts the clock on the other deadlines.
- Draft the Operating Agreement before any capital is contributed or trades placed.
- Apply for an EIN once state formation is confirmed. This takes minutes online.13Internal Revenue Service. About the Employer Identification Number
- Open a business bank account and fund it with the capital contribution that will move to the brokerage.
- Open the brokerage account in the LLC’s name, providing the EIN, Articles of Organization, and Operating Agreement.
- If electing S-Corp, file Form 2553 within 75 days of formation. Miss the window and you wait until the next tax year.
- If electing MTM as a new entity, place the statement in your books and records within two months and 15 days of the election year’s first day.2Internal Revenue Service. Topic No. 429, Traders in Securities
- Begin trading and logging activity. Daily records start on day one and are your primary defense in an audit.
Many traders form the LLC in late December so the entity exists on January 1 of the new tax year, giving the maximum window for the MTM election and Form 2553. Forming mid-year leaves the same deadlines in place, but the shortened trading period for that first year may weaken your TTS case because you’ll have fewer months to demonstrate substantiality and continuity. Working with a CPA or tax attorney who specializes in trader taxation before you file the first form is the most cost-effective step in the entire process.