A Chrome extension that adds a native-looking sector-exposure card to your Fidelity portfolio. Recommendation-only; all data stays local.

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Fidelity's portfolio summary shows you an asset allocation donut (stocks vs. bonds vs. cash), but nothing about your sector mix. SectorScope is a Chrome extension (Manifest V3) that adds a card looking like it shipped with the site: it reads the holdings already on the page, resolves each fund/ETF to its true sector breakdown, and charts your real Information-Technology-vs-Financials-vs-everything-else exposure. Then, against a target allocation you set, it tells you what to buy with your available cash to close the gaps, and optionally what to trim.

It never asks for your credentials, never places a trade, and never sends your holdings anywhere. Everything runs in your browser.

Note

SectorScope is recommendation-only and provides estimates. It does not place, pre-fill, or submit trades, and it is not affiliated with or endorsed by Fidelity Investments.

Features

• 🍩 Native-looking sector donut — a custom SVG chart (no CDN libraries) styled to match Fidelity's own Asset allocation card, injected right into the Summary page's masonry layout.
• 🧮 True look-through exposure — resolves each holding to its underlying sector mix via Fidelity's ETF and mutual-fund composition endpoints (by symbol and CUSIP), so a total-market fund is split across sectors instead of dumped into "Other."
• 🎯 Target allocation you control — set a per-sector target (per Fidelity account), map each sector to a preferred buy ticker, and see current-vs-target at a glance.
• 💸 Holdings-aware buy recommendations — a greedy allocator deploys your available-to-trade cash into the most underweight sectors, preferring instruments you already hold before introducing a new ticker.
• ✂️ Optional trim suggestions — sector-level sell-to-target amounts for overweight sectors, restrictable to tax-advantaged accounts so you don't trigger avoidable capital gains.
• 🔒 Local by design — target allocations and a short-lived sector-exposure cache live in chrome.storage.local. No account data ever leaves the browser.

Screenshots

Toolbar popup — quick per-account glance & toggles	Options — per-account targets, buy tickers, and behavior

All screenshots use synthetic holdings and made-up tickers (TCHGX, INDUX, …) — never real account data.

How it works

flowchart LR
    A([Fidelity Summary page]) --> B[Content script<br/>reads holdings + cash]
    B --> C[Service worker<br/>fetches sector composition]
    C -. opt-in .-> Y[Yahoo lookup<br/>unclassified funds]
    Y --> D
    C --> D[Aggregate → sector %]
    T[(Target allocation<br/>chrome.storage.local)] --> D
    D --> E[Allocate cash to<br/>underweight sectors]
    E --> F([Render card<br/>donut · buys · trims])

    classDef proc fill:#1b2438,stroke:#28324d,color:#e6e9ef;
    classDef edge fill:#243056,stroke:#6c7ba6,color:#c9cfdb;
    classDef opt fill:#202a3f,stroke:#6c7ba6,color:#9aa4b7,stroke-dasharray:4 3;
    classDef out fill:#ef5f6e,stroke:#c94656,color:#20131a,font-weight:bold;
    class B,C,D,E proc;
    class A,T edge;
    class Y opt;
    class F out;
    linkStyle default stroke:#6c7ba6,stroke-width:1.5px;

Loading

Every step runs locally. The only network requests are the sector-composition lookups described in Privacy & permissions — never your holdings, balances, or account numbers.

Privacy & permissions

SectorScope handles private financial data, so it is built to keep that data on your machine:

• No credentials. It never asks for, reads, or stores your Fidelity username, password, cookies, or CSRF tokens.
• No trading. It cannot place, pre-fill, or submit orders. It only reads and recommends.
• No analytics, no backend. There is no server. Your holdings, balances, and account numbers are never transmitted anywhere.
• Local storage only. Your target allocations and a 7-day sector-exposure cache live in chrome.storage.local. Account identifiers are hashed before use.

Every permission is requested for one concrete reason:

Permission	Why it's needed
storage	Save your target allocations and cache sector-exposure data locally.
digital.fidelity.com	Read the holdings and available-to-trade balance from the portfolio page you're viewing, and inject the card.
research2relay.fidelity.wallst.com	Fetch ETF sector exposure by symbol.
fundresearch.fidelity.com	Fetch mutual-fund composition by CUSIP.
query1.finance.yahoo.com, fc.yahoo.com	Opt-in only — look up sector data for funds Fidelity doesn't classify (e.g. some 401(k)/403(b) institutional funds). Off by default; enable it in Settings.

All Fidelity fetches are made with credentials: 'omit' and an 8-second timeout.

Install

SectorScope isn't on the Chrome Web Store yet. A prebuilt, ready-to-load zip is attached to every GitHub Release — no build tools required.

1. Download sectorscope-dist-v<version>.zip from the latest release.
2. Unzip it. You'll get a sectorscope-<version>/ folder that contains manifest.json.
3. Open chrome://extensions, enable Developer mode (top-right), click Load unpacked, and select that unzipped sectorscope-<version>/ folder — the one containing manifest.json, not its parent.

Then log in to Fidelity and open Portfolio → Summary. The card injects below the Asset allocation card. If it asks you to visit your Positions page once, do that and return to Summary (Positions primes the holdings data). The MV3 service worker shows "Inactive" on chrome://extensions until a Fidelity page wakes it — that's normal.

Build it yourself

Prefer to build from source? Requires Node 18+:

git clone https://github.com/drogers0/SectorScope.git
cd SectorScope
npm install
npm run build      # outputs the loadable extension to dist/

Then Load unpacked the resulting dist/ folder (the one containing manifest.json) exactly as above.

Development

npm run build       # build all Vite configs + copy manifest/icons/styles → dist/
npm run test        # vitest (node env) — 416 tests
npm run typecheck   # tsc --noEmit (both tsconfigs)
npm run lint        # eslint src

Architecture:

• src/content/ — content script: detects the page, reads holdings/balances, injects the card, survives SPA navigation.
• src/background/ — MV3 service worker: cross-origin sector-exposure fetches + cache.
• src/core/ — framework-free engine: sector mapping, aggregation, and the buy/trim recommendation logic (the primary unit-test surface).
• src/ui/ — the vanilla-TS card island (donut, legend, tables).
• src/popup/, src/options/ — React surfaces for quick toggles and the target-allocation editor.
• src/fidelity/ — parsers for Fidelity's positions/balances/account endpoints, driven by sanitized fixtures.

Important

Unit tests run in a node env with no DOM, no service worker, and no live Fidelity endpoints. Passing typecheck / lint / test is necessary but not sufficient — build, load the unpacked dist/ in a Chrome dev window, and verify the change on a real Fidelity page before calling it done.

Never commit real account data. Tests, fixtures, and screenshots must use synthetic values only.

Contributing

Issues and pull requests are welcome. Please keep changes covered by tests, run npm run typecheck && npm run lint && npm run test before opening a PR, and never include real brokerage data in code, fixtures, screenshots, or commit messages.

License

MIT © David Rogers

_{SectorScope provides estimates and does not place trades. Not affiliated with Fidelity Investments.}