Custom Assets

A custom asset is a fund you name that is based on exactly one catalog fund. For example, a custom asset based on VTSAX named “My Aggressive VTSAX”. It is not a new fund with its own market history. It borrows the parent fund’s market data wholesale, then lets the scenario add its own return and tax-mix assumptions on top. The idea is “same fund, my own assumptions”. You can model a fund under your own return bet without editing the shared catalog every other plan draws from.

A custom asset lives on the scenario and carries its own name, separate from the parent’s ticker.

What a custom asset inherits

A custom asset inherits the parent fund’s catalog data: its returns, asset class, and distributions. It never inherits the parent’s scenario-level asset return override. This is the one subtle rule and the design’s defining behavior.

• If the parent carries no override, a custom asset with no override of its own projects identically to the parent, year for year. It is a clone of the parent’s underlying returns.
• If the parent carries a scenario override, say one holding catalog VTSAX to 1% nominal, a custom asset based on VTSAX ignores it. It keeps compounding at the parent fund’s own historical return. That override reaches the parent’s own holdings only, never the custom asset’s.

In every projection a custom asset behaves as an ordinary catalog fund. Its history is the parent’s. It inherits the parent’s full series, including any reconstructed pre-history a short-history parent carries, so it reaches back to the catalog’s start just as the parent does. Two custom assets based on the same parent are fully independent funds, with distinct balances, distinct overrides, and no bleed between them.

The parent must be a catalog fund

A custom asset’s parent is always a catalog fund, never another custom asset. You can only base a custom asset on a fund from the shared catalog. If a plan names a parent the current catalog no longer carries, the plan fails up front with an error naming the missing fund, rather than failing later on a missing price.

A custom asset’s own overrides

On top of the inherited returns, a custom asset may carry the same return-rate and tax-mix overrides a catalog fund can. They behave identically, including which runs each reaches, and are covered in full in asset return overrides. Without one, the custom asset falls back to the parent’s value for it.

The one difference is the target. A catalog override lands on the catalog fund and every plain holding of it. A custom asset’s override lands on the custom asset alone, leaving both the shared catalog fund and any sibling custom asset of the same parent untouched.

A custom asset is named in a holding or a target allocation exactly the way a catalog fund is. How an account rebalances a mix of catalog and custom holdings is covered in allocation, lots, and selling.

A price per share

A custom asset can carry a price per share at plan start, as a company stock does (stock compensation). Lots and holdings of it can then be held in shares, in any taxable or retirement account, not only an Employer stock plan account. You enter shares in the stock editor on the Income page. It lists the accounts that already hold the stock, plus the account where kept shares go. Any lot or holding of it can be switched between shares and dollars at the price.

Shares need the price: shares of a custom asset with no price, or of a catalog fund, are refused. FinZot values shares at the price. Changing the price changes what share holdings are worth and leaves amounts entered in dollars as they are. The price can’t be removed while shares of the asset are held or an RSU grant pays in it.