Fidelity Basket Portfolios are an underused product. Most people who know they exist either never build one or build one by hand and never rebalance it. Arithmos is the layer that takes the construction off your plate while Fidelity keeps doing what it does best: holding the wrapper.
When the Basket Portfolios UI alone is enough
- You have ten or fifteen names you already know you want.
- You will not rebalance more than once a year.
- You have no screen rule to apply, you just want the names you typed in.
- You do not need a backtest before deploying capital.
When the Arithmos export wins
- The screen has more than three or four conditions. Hand-screening a quality-factor basket against the Russell 1000 is a weekend of work; Arithmos returns it in under a minute.
- You want backtest, drawdown and attribution before committing. Baskets do not provide these natively.
- You want the same rule re-run on a schedule and the Basket refreshed automatically. Arithmos handles the screen, you upload the new CSV.
- You want the rule documented in plain English so a partner, accountant or future-you can audit it later.
- You want tax-loss harvesting overlays as a separate prompt that share the same screen.
Fees
Fidelity Basket Portfolios charges its own subscription per basket. Arithmos charges the subscription. Trades on Fidelity-listed names are commission-free as usual. We do not mark up the broker leg.
FAQ
Will the Arithmos export load into Fidelity Basket Portfolios?
Yes. Arithmos generates a CSV in the columns Basket Portfolios accepts. Open Basket Portfolios, Add Securities, upload the file.
Does this work in an IRA?
Yes. Basket Portfolios are supported in taxable, IRA and Roth IRA accounts at Fidelity. The wrapper handles the tax treatment.
