Concentrated wealth is crumbling and taxes are to blame, says advisor

Concentrated stock wealth has turned from a symbol of success into a potentially dangerous financial trap, and the real threat isn’t the market — it’s the taxes investors trigger when they try to diversify.

The problem is bigger than a few lucky trades. As stock-based compensation explodes across tech and finance, more investors are waking up to the risks of lopsided portfolios built around a handful of names. What once seemed like a badge of success—riding a single stock to massive gains—can quickly become a financial trap, where any attempt to diversify threatens to unleash staggering tax liabilities.

Greg Warner, CIO and wealth advisor at Adero Partners, has spent decades guiding clients through this dilemma. His strategy isn’t about finding a single escape hatch—it’s about layering sophisticated defenses, combining institutional trading tactics, tax-optimized planning, and real-time oversight to dismantle risk without triggering financial fallout.

Which tool fits?

For clients who want to diversify without an immediate sale, Warner leans first on exchange funds.

“The first one that’s fairly well known historically is using exchange funds,” Warner explains. Investors contribute concentrated positions—like Nvidia or Tesla—into a pooled basket of stocks across many participants.

“You get diversification from essentially day one,” he says, with the added benefit of preserving the original cost basis. Although not the most tax-efficient option, it offers an immediate reduction in single-stock risk.

For those seeking a more active strategy, Warner recommends bolting a long/short strategy onto the existing stock holdings. By harvesting losses systematically—short side in rising markets, alongside falling ones—investors can chip away at the position over time.

“In theory, in either direction, if markets move up or down, they’re able to harvest losses, then you can start to chip away at selling the stock,” he says.

Direct indexing rounds out the trio. It’s a softer approach: an index manager mirrors the performance of a benchmark while systematically harvesting tax losses.

“That one is a reasonable option, but it’s probably less aggressive,” Warner explains. For Adero’s client base, the real power lies in layering strategies—using both long/short harvesting and exchange funds together when necessary.

Hidden tax landmines and liquidity traps

As private market investments grow in popularity, Warner warns that each asset class carries different tax implications.

“There’s some innate tax benefits to private investing,” Warner says, especially in private equity where value appreciation is often deferred until an exit, allowing for long-term capital gains treatment.

Not all private assets are created equal, though. “If it’s private credit, you may get more ordinary income taxation with that kind of stuff,” Warner explains. Annual cash flows can mean regular tax hits, compared to the deferred, back-ended gains typical of private equity.

Funding capital calls can also introduce friction. When clients must sell appreciated public assets to meet capital demands, they may realize taxable gains at inopportune times. Warner’s advice: plan liquidity carefully and time asset sales to offset realized gains wherever possible.

Turning volatility into a tax asset

At Adero, technology plays a central role in spotting tax-saving opportunities. Their trading systems constantly monitor portfolios for deviations outside custom tolerance bands or for harvesting candidates.

“We have algorithm learning in the background of our trading systems,” Warner says. If the system flags a tax-loss opportunity, it is escalated for human review. “Then it’s up to our advisors to go in and essentially approve,” Warner explains, ensuring oversight and strategic judgment are layered onto automation.

Even ESG and sustainable portfolios get the same rigorous treatment. Warner points out that value-driven portfolios may underperform energy-heavy benchmarks during oil booms, but the underlying tax management discipline—loss harvesting, rebalancing, and drift control—remains identical.

“Sustainability approaches that we use are filtered through a lens of values and sustainability metrics,” Warner says. But that doesn’t exempt them from the same tax scrutiny applied to traditional portfolios.

Warner’s message is clear: concentrated wealth can be a tax time bomb. The solution isn’t one magic trick—it’s a layered defense combining institutional strategies, adaptive software, and advisor judgment.