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 in the extension. Sign in on the web app to save up to three accounts and connect one read-only Plaid sync (Plaid Link is web-only); 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 is where signed-in features and Plaid connections live. Free signed-in already covers Overview, Holdings, Accounts, Fees, Compare, and Trade Impact with one web Plaid connection. If you have accounts at multiple brokerages and want unlimited consolidation without visiting each tab, Plus adds unlimited web Plaid sync and the deeper Analysis dashboards (Allocation, Concentration, Performance). Google Sign-In keeps saved settings and target allocations across devices on Free and Plus.

These features are genuinely useful. But I designed the free tier to be complete for single-broker use: local extension analysis, limited signed-in web, one web Plaid connection, and a top insight on your portfolio, not a crippled demo. If you want unlimited web Plaid sync and Plus Analysis, that's Plus.

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