The Ultimate Tax-Aware Duo.

Most investors use one tax strategy at a time. They harvest losses when the market dips, or they borrow against their portfolio when they need liquidity. Rarely both. And almost never in a way that makes them work together.

Direct indexing and box spreads are the two strategies I keep coming back to – not because either one is flashy, but because they compound off each other in a way that most advisors never think about.

Start With Direct Indexing

Direct indexing means owning the individual stocks inside an index rather than a fund. The exposure is almost identical to an ETF. The difference is that you own each security separately – which means you can harvest losses at the individual stock level.

When a position dips below your cost basis, you sell it, realize the loss, and replace it with something similar. The index exposure stays intact. The loss goes into the bank. This happens continuously – not just when the market is down, but in up markets too, because individual stocks move independently of the index.

That loss bank is the key. Harvested losses do not expire. They accumulate in the background, year after year, ready to be deployed against gains from a real estate sale, a business exit, an RSU vest, a private equity distribution – whatever generates income you need to offset.

Now Add Box Spreads

A box spread is a four-leg options structure on a broad index – SPX or XSP – that creates a fully hedged position with a known payoff at expiration. The difference between what you collect today and what you owe at expiration is, effectively, an interest rate. Set by the market. Not a bank. Typically close to Treasury rates.

So you can borrow against your portfolio at near-Treasury rates without a bank, a credit check, or a forced sale of appreciated positions. Your portfolio stays fully invested, and the interest is potentially tax-deductible.

That last part matters. The interest expense on a box spread loan can be deducted against investment income – including the gains your direct indexing strategy is offsetting. You are not just building a loss bank. You are also generating deductible interest that further reduces your taxable income.

Why They Work Better Together

Direct indexing solves the gain problem. Box spreads solve the liquidity problem. But the real insight is that they reinforce each other on the tax side.

The direct indexing engine produces losses you can use anywhere. The box spread loan produces deductible interest. Both reduce your taxable income. Both let you stay invested and avoid triggering taxable sales. Used together, you are running a continuous tax reduction machine on top of a fully invested portfolio.

Most advisors offer one or the other. Very few can execute both – and fewer still think about how they interact. At STQ, this is the combination we build around for clients who want to keep more of what they earn.