Funding a direct indexing account with mutual funds

When mutual funds are used to fund a direct indexing account, the trading, tax, and portfolio construction implications can differ meaningfully from other in-kind assets. Because mutual funds are treated differently within direct indexing frameworks, their use can introduce unintended tax consequences, portfolio imbalances, and operational constraints that advisors need to evaluate carefully before transferring them.

A direct indexing separately managed account can be a tax-efficient way to get equity index exposure. The separate account structure provides customization options not available in index mutual funds and exchange-traded funds (ETFs), including stock and sector restrictions, business involvement screens, capital gains constraints, and in-kind funding.

That last point – in-kind funding – means a direct indexing account can be opened using cash and/or securities. If a client owns securities that are constituents of the target index and carry embedded gains, a direct indexing account can act as a “sponge,” allowing those securities to be transferred in-kind without triggering an immediate taxable sale in accordance with the capital gains budget. If a transferred security represents a large overweight or concentrated position, they can be sold gradually when realized losses elsewhere in the account can offset those embedded gains.

Roughly one-third of new accounts opened at Natixis are funded entirely with cash, while the remainder are funded with a combination of cash and securities – typically individual stocks and ETFs. Some separate account platforms allow mutual funds to be transferred into a direct indexing account, which is why it’s important to understand the nuances involved.

Mutual funds are not index constituents

Mutual funds are not index constituents. While that may sound obvious, it’s an important point because it typically means those positions are liquidated first and may result in recognized gains. Eliminating or reducing nonindex holdings helps the portfolio manager build an index tracking portfolio. If the client wants to hold onto the fund or defer realizing gains, it should be held in another account.

A money market mutual fund, however, can typically be converted to cash quickly with little or no capital gains impact.

If the objective is to generate tax losses to help reduce a concentrated index position – Amazon, for example – it’s important to understand trade sequencing. Mutual funds and other nonindex positions in the account may take priority over trimming the Amazon position. And many firms don’t accommodate a “do not sell” restriction on mutual funds, so the trade sequencing will follow the manager’s algorithm. Client expectations should be set accordingly.

The mutual fund’s underlying holdings are ignored

Let’s assume a $100,000 direct indexing account is funded with $25,000 of a semiconductor-focused mutual fund and $75,000 in cash. Semiconductor stocks are part of the information technology sector, and we’ll assume tech stocks represent 33% of the S&P 500®’s weight.

One might expect that the underlying holdings of the mutual fund would be considered when building the direct indexing account – i.e., there’s already 25% in tech stocks so just buy 8% more – but that’s not the case. Roughly one-third of the $75,000 would still be used to purchase individual technology stocks, resulting in nearly 50% of the initial portfolio in tech.

This is an extreme example, as most mutual funds are more diversified, but it illustrates the point: The mutual fund’s holdings – today or in the future – aren’t accounted for when building the direct indexing portfolio.

Cost-basis reporting is better when it’s original cost instead of average cost

For mutual funds, most custodians default to the IRS-permitted average-cost-basis methodology. Under average cost, the basis is calculated by averaging the purchase price of all shares owned.

This approach has the effect of diluting the gains of older, appreciated shares and allocating gains to newer, more expensive shares. In a rising market, the average cost approach is generally less tax efficient because it doesn’t allow for selective tax-lot selling. As a result, opportunities for tax loss harvesting mutual fund shares are reduced as the portfolio manager has less control over managing gains and losses.

To illustrate, here is a simple example of a mutual fund purchased twice over the past five years. It’s easy to see that using average cost eliminates the flexibility in choosing tax-efficient shares to sell: Under original cost, the 5/15/2026 tax lot has a $1.00 unrealized loss, but under average cost, it has a $4.00 unrealized gain.

If average basis has been elected, or was the custodian’s default selection, the ability to change cost-basis methods depends on whether the shares are covered (purchased after 2012) or noncovered (purchased before 2012). For covered shares, a change away from average basis is generally prospective only and does not restore the original cost basis of shares already averaged. For noncovered shares, the election is generally more restrictive once average basis has been used.

Platform capabilities vary, and some custodians support only a limited set of mutual fund cost-basis methods, while others allow broader lot-selection options for covered shares.

The platform must allow for specific identification when selling mutual fund shares

Direct indexing managers rely on lot-level data when making trading decisions. Each tax lot is evaluated for sale based on its unrealized loss and holding period. When sell orders are generated, managers expect the specific lots they’ve identified to be executed by the sponsor firm, as instructed.

If the platform cannot support specific lot identification – or defaults to another cost-basis disposal method such as FIFO (first in, first out) – the tax consequences can vary significantly from expectations. In some cases, intended losses may turn into realized gains.

Short-term capital gains “gotcha”

Not specific to direct indexing accounts, but important nonetheless, net short-term gains distributions from mutual funds are taxed as ordinary income and reported on Form 1099-DIV. Because net short-term capital gains distributions are taxed as ordinary income, capital losses do not directly offset those distributions. Instead, capital losses first offset capital gains, and only then can up to $3,000 of net capital loss offset ordinary income.

If mutual fund shares are sold at a loss after being held for six months or less, and the fund distributes long-term capital gains on those shares during the holding period, the loss is recharacterized from a short-term loss to a long-term loss to the extent of the distribution. Because long-term losses are generally less valuable than short-term losses, this can reduce tax efficiency.

Direct indexing investing strategies

Direct indexing can play a valuable role in a tax-efficient investment strategy, especially for high-net-worth investors. Let us help you create portfolios that put taxes first.