Research · Tax-loss harvesting
Research-backed guidance on improving after-tax outcomes. Built for advisers and portfolio managers who need evidence, not promises.
The economic case
Taxes are one of the largest controllable costs in portfolio management. Tax-loss harvesting targets this cost directly, not by predicting markets, but by systematically improving how much of your returns survive after tax.
Systematic tax-loss harvesting can add 0.5% to 4% per year to after-tax returns, depending on portfolio composition and market conditions (Vanguard 2024). The benefit compounds: capital that would have gone to taxes remains invested.
Tax-loss harvesting does not require a view on where markets are heading. It operates on observable data: unrealised losses, cost basis, holding periods. Volatility creates more opportunities, not more risk.
Tax-loss harvesting does not compete with asset allocation, diversification, or long-term portfolio design. It focuses on how much of those returns remain after tax, a dimension often overlooked in performance discussions.
The mechanics
The process is mechanical and rules-based, not discretionary. Each step can be documented, audited, and consistently applied across accounts.
Illustrative only. Example uses a $32,000 position (250 shares at a $100 cost basis) at a 32% marginal rate. Actual outcomes depend on portfolio composition, jurisdiction, and holding periods.
Review portfolio positions trading below their initial purchase price (cost basis). Use meaningful thresholds to focus on losses that deliver real after-tax value after transaction costs.
Compare unrealised losses against realised gains for the tax year. Determine which losses can offset current gains and which may carry forward under local rules.
Reinvest proceeds into a highly correlated but distinct security to maintain portfolio exposure. Validate correlation, tracking error, and sector/factor similarity.
Read: replacement asset selectionRecord the rationale for each decision: lots evaluated, lots selected, replacement logic, and expected tax impact. Export documentation for compliance or client review.
Read: lot-level selectionWhere it adds value
Tax-loss harvesting is not always the right move. Understanding where it delivers real benefit, and where it doesn't, is essential to using it well.
Governance
The most common concern from advisers is not whether tax-loss harvesting works, but whether it creates compliance risk. The short answer: a rules-based process is easier to defend than a discretionary one.
Every decision follows predefined thresholds and constraints: loss size, turnover limits, holding periods, concentration limits. Rules reduce behavioural risk and make outcomes consistent across clients.
Each action links to the client mandate, rule triggers, suitability checks, replacement selection logic, and client communications. The rationale is visible, not implicit.
Generate reports for internal compliance review, client reporting, or external audit. Lot-level selection, trade rationale, and expected impact are documented at every step.
After-tax returns are the new alpha for advisers.
Lumvest · 2026 thesis
Global coverage
Tax rules differ across markets. Holding periods, offset limits, anti-avoidance provisions, and carryforward treatment vary by jurisdiction. Our research covers the rules that matter for your clients.
Research library
Our research library covers the mechanics, evidence base, and practical considerations of tax-loss harvesting in detail.
The complete framework: mechanics, anti-avoidance rules, replacement strategies, and common mistakes across jurisdictions. A cross-market reference for advisers managing taxable portfolios at scale.
Read the guideWhat reported negative gearing and CGT discount changes imply for after-tax listed portfolios and systematic loss harvesting.
Read articleHow to evaluate individual tax lots to maximise harvested losses while avoiding unnecessary gains. Ranking logic and worked examples.
Read articleCorrelation math, tracking error analysis, factor exposure checks, and a defensible scoring model for replacement selection.
Read articleWhy rules-based tax management is more repeatable and defensible than forecast-driven investing.
Read articleComparing tax-loss harvesting to timing-based strategies on consistency, controllability, and long-term compounding.
Read articleTrend-driven strategies depend on timing, conviction, and luck. Tax-loss harvesting relies on predefined rules and observable data.
Read articleUpload historical trades, review the analysis, and export documentation for compliance or client review. No account required.
