Automated tax-loss harvesting for taxable portfolios (reduce taxes passively)

Taxable investors, financial advisors, and digital brokers face a persistent tax drag in non-retirement brokerage accounts because realizing losses opportunistically requires high-frequency, tax-lot-aware trading and precise wash-sale management—activity that is manual, error-prone, or simply unavailable at scale. With an estimated $50 trillion in taxable retail assets, that inefficiency is a meaningful pain point for cost-conscious households and advice platforms focused on after-tax returns. You could build an automated tax-loss harvesting platform that integrates with brokerages via APIs, executes micro-trades including fractional-share replacements, and maintains real-time tax-lot accounting and wash-sale logic to harvest losses continuously while producing compliant tax reporting. Priced at roughly 0.01% annual platform fee, the addressable market is about $5.0 billion; combined with strong secular trends (robo-advice growth, API-enabled brokerages, and investor emphasis on after-tax performance), the concept scores highly for opportunity (Market Score 92/100, Revenue Potential 88/100). To stand out, focus on custody-level integration, a robust real-time wash-sale engine, portfolio-level after-tax optimization, and flexible white-label offerings for advisors rather than a generic overlay. The strengths are low marginal cost per account and a very large TAM; the key challenges are proving durable net-after-fee tax savings at scale, securing deep brokerage partnerships, and navigating compliance and reporting complexity so clients and fiduciaries can trust the outcomes.