Why we built Prismfolio

A few years ago I had brokerage accounts at both Fidelity and Schwab. Not unusual, a lot of people end up that way through old jobs, rollovers, or just inertia. The problem was that I had no clean picture of my combined allocation. I knew roughly what I owned, but I couldn't see stocks vs bonds vs cash as a single number without logging into two separate tabs and doing mental arithmetic.

So I did what most people do: I started Googling. Every result sent me toward one of three things, a robo-advisor that wanted to manage my money, a personal finance platform that wanted full read-write access to my accounts, or a spreadsheet I'd have to maintain manually forever.

None of those were what I wanted. I wanted a read-only, instant view of what I already had, without handing my credentials to anyone.

Why a Chrome extension made sense

The answer turned out to be sitting right there in the browser. When you log into Fidelity or Schwab, your holdings are already on the page, rendered in HTML, loaded into the DOM. A Chrome extension can read that data locally, in your browser, without it ever leaving your device.

That's the architecture Prismfolio uses. It reads the portfolio data that's already displayed on your brokerage page. No API calls to our servers. No credentials stored anywhere. No account required to use the free tier. The analysis, allocation breakdown, sector exposure, overlap between holdings, happens entirely inside your browser using local JavaScript.

This isn't a workaround. It's the correct privacy model for this use case. Your brokerage already authenticated you. Prismfolio just helps you see what's there more clearly.

The thing about "account linking"

Most financial tools default to OAuth or Plaid connections. Those are legitimate technologies and we use Plaid ourselves in other products. But for portfolio visualization, full account linking is overkill. It's a heavier trust ask than the job requires.

When a tool asks you to link your Schwab account, you're creating a persistent connection, a token that sits on someone else's server, refreshing periodically, with access to your balance and transaction history. That connection has to be maintained, secured, and eventually revoked. For a portfolio overlay, you don't need any of that. You just need the data that's already in front of you.

Prismfolio's free tier keeps broker-page analysis local. Optional sign-in adds up to three saved accounts and one read-only Plaid sync; we store only what sync requires, encrypted at rest. Anonymous extension use on a broker tab still never sends portfolio data to us.

What the web app adds, and why it's optional

The Prismfolio web app exists for people with more complex situations. If you have accounts at multiple brokerages and want them consolidated automatically, without manually visiting each tab, Plaid investment sync handles that. The web app also adds Google Sign-In so your saved settings and target allocations persist across devices.

These features are genuinely useful. But I designed the free tier to be complete for single-broker use: up to three accounts, one Plaid sync, and capped insights, not a crippled demo. If you want unlimited sync and the full web workstation, that's Plus.

That was the product I wanted when I started. Nobody had built it, so I did.