Not all investments are created equal in the eyes of the IRS. A simple index fund held in a brokerage account generates a consolidated 1099 at year-end, flows to Schedule D, and matches the IRS’s data automatically. The reporting is largely done for you.
Other investments sit in territory where reporting is fragmented, valuations are subjective, documentation is sparse, or the tax treatment depends heavily on decisions the investor makes themselves. That’s where scrutiny concentrates — not because certain investments are suspect, but because certain structures create a higher statistical probability of errors, omissions, or aggressive positions that don’t hold up under review.
Understanding which categories draw more attention — and why — helps you approach them with the documentation habits that keep legitimate activity clean.
Cryptocurrency and digital assets
Crypto sits at the top of the list, and the reason is structural rather than punitive. The IRS classifies cryptocurrency as property, which means a much wider range of activities create taxable events than most investors realize. Selling for cash is obvious. But trading one coin for another is also taxable. Using crypto to buy something is taxable. Receiving staking rewards is income. Each of these requires tracking cost basis, fair market value at the time of the transaction, and holding period.
Now multiply that across dozens or hundreds of transactions across multiple exchanges, decentralized platforms, and personal wallets — many of which provide incomplete or inconsistent records — and the probability of incomplete reporting increases dramatically even for investors acting in good faith. The IRS’s data-matching system flags discrepancies between exchange-reported activity and what appears on returns, and those discrepancies generate notices at scale.
Crypto isn’t scrutinized because it’s suspicious. It’s scrutinized because it’s structurally complex and historically under-reported.
Rental real estate with repeated losses
Rental real estate is one of the most common investment categories, and legitimate rental losses are fully allowed — but the rules around how those losses can be used are specific and frequently misapplied.
Under the passive activity rules, rental losses generally can only offset other passive income, not ordinary income like wages. There are exceptions — taxpayers who actively participate in their rental activity can deduct up to $25,000 of losses against ordinary income if their modified AGI is below $100,000, with a phase-out between $100,000 and $150,000. And taxpayers who qualify as real estate professionals — spending more than half their working hours and at least 750 hours per year in real property activities — can deduct rental losses without limit.
What draws scrutiny isn’t owning rental property or having losses. It’s when a high-income taxpayer reports large rental losses year after year, particularly when claiming real estate professional status with a full-time job in an unrelated field, or when the losses come from aggressive depreciation elections or cost segregation studies that produce deductions well beyond what simple straight-line depreciation would generate.
Offshore accounts and foreign investments
U.S. taxpayers owe tax on worldwide income regardless of where it’s earned or held, and certain foreign financial assets require reporting beyond the standard tax return — the FBAR for accounts exceeding $10,000, Form 8938 under FATCA for higher thresholds, and various other forms depending on the type of asset.
The penalties for failing to file these informational forms are severe — up to $10,000 per violation for non-willful failures, and significantly higher for willful violations — and they apply even when the underlying income is reported correctly. This creates a compliance trap for taxpayers who have foreign accounts or investments but aren’t aware of the reporting requirements beyond their tax return.
The IRS has invested significantly in international enforcement through information-sharing agreements with foreign governments and financial institutions. Offshore accounts that were once effectively invisible have become traceable through FATCA reporting by foreign banks. The enforcement environment for foreign accounts is considerably more intense than it was a decade ago.
Syndicated conservation easements
Conservation easements — legal arrangements where a landowner donates development rights to a conservation organization — are legitimate tax tools with a long history. The scrutiny arises in a specific subset: syndicated arrangements that promise deduction multiples far exceeding the cash contributed.
In these transactions, investors contribute cash to a partnership that then donates a conservation easement and claims a charitable deduction based on an appraisal of the development rights foregone. When that appraisal values the donated rights at three or four times the cash invested, the IRS scrutinizes the valuation methodology, the appraisal qualifications, and whether the arrangement has economic substance beyond generating a tax deduction.
The IRS has listed certain syndicated conservation easements as “listed transactions” — a designation reserved for tax shelters with a history of abuse — which triggers additional disclosure requirements and heightens examination risk.
High-volume trading activity
Frequent traders face specific reporting challenges that increase error probability. Thousands of transactions in a year create thousands of opportunities for cost basis errors, wash sale miscalculations, and incorrect holding period classifications. The wash sale rule — which disallows a loss if a substantially identical security is purchased within 30 days before or after the sale — is particularly easy to trigger inadvertently in active trading accounts.
Most brokers handle wash sale tracking automatically on 1099-B forms, but the tracking becomes complex when the same securities are held across multiple accounts or when options are involved. Discrepancies between brokerage-reported figures and what’s on the return are a common source of CP2000 notices for active traders.
What draws scrutiny across all these categories
| Investment type | Reporting complexity | Self-reporting risk | IRS attention level |
|---|---|---|---|
| Standard brokerage stocks/ETFs | Low | Low | Low |
| Rental real estate | Moderate | Moderate | Medium |
| Cryptocurrency | High | High | High |
| Foreign accounts/investments | High | High | High |
| High-volume day trading | High | Moderate | Medium-High |
| Syndicated conservation easements | Very High | Very High | Very High |
The common thread across all scrutinized investments is structural, not moral. They share one or more characteristics: reporting is fragmented across multiple sources, valuation involves judgment rather than objective market data, losses or deductions reduce large amounts of income, or there’s a documented history of the category being used for aggressive tax positions that don’t reflect economic reality.
Scrutiny follows complexity and inconsistency. Accurate documentation, consistent reporting, and positions that reflect actual economic substance are what keep legitimate activity in any of these categories out of trouble.
Frequently asked questions
Does owning cryptocurrency automatically increase my audit risk? Not automatically — but incomplete or inaccurate crypto reporting is one of the most common triggers of IRS notices due to the complexity of tracking taxable events across multiple platforms.
Are rental property losses a red flag? Legitimate rental losses are fully allowed. What draws attention is repeated large losses combined with high ordinary income elsewhere, particularly when passive activity rules are being stretched or real estate professional status is claimed without adequate time documentation.
Should I avoid aggressive investments to reduce audit risk? Avoiding legitimate investments out of fear isn’t necessary. The goal is accurate reporting and solid documentation, not avoidance.