In short
StackViewer connects to Vanguard (US) through SnapTrade using a read-only connection. It imports your fund and ETF positions, your transaction history and your settlement-fund cash balances, merges them with your other brokers into one portfolio, and then analyses the decisions behind the numbers — entry and exit quality, opportunity cost, and the patterns in how you invest. Connecting Vanguard is free. One honest caveat up front: if you are a pure three-fund, buy-and-hold Vanguard investor who trades twice a year, StackViewer's decision layer has almost nothing to work with — read the fit warning below before you sign up.
Is StackViewer even right for a Vanguard investor?
We would rather lose the signup than waste your time, so here is the blunt version. If your Vanguard account is a classic three-fund, set-and-forget portfolio — a total US market fund, a total international fund and a bond fund, rebalanced once a year — then you are our anti-customer, and StackViewer will bore you. Our entire reason to exist is analysing the decisions behind your returns: why you entered, why you sold, whether emotion or conviction drove the trade. A portfolio that sees two transactions a year gives that decision layer nothing to chew on. Vanguard's own performance page and a simple spreadsheet will serve you better and cost nothing.
Where StackViewer earns its place is the Vanguard-plus-a-second-broker investor. If Vanguard holds your long-term core — the index funds you never touch — but you also run a more active account elsewhere for individual stocks or thematic bets, then you have a real problem StackViewer solves: your true, blended return and risk live in two different apps that do not talk to each other. That is the reader this page is written for, and if it describes you, keep reading.
What syncs from Vanguard
Positions
Your holdings across Vanguard brokerage accounts — mutual funds, Vanguard and third-party ETFs, and individual securities — with quantities, market value and cost basis where Vanguard exposes it. Fractional mutual-fund units come across at full precision.
Trade history
Buys, sells, exchanges between funds, and dividend reinvestments, imported as dated transactions so StackViewer can reconstruct each lot and score the decision behind it.
Cash & balances
Settlement-fund cash and money-market sweep balances, so your uninvested cash is counted in your allocation rather than silently ignored.
Dividends
Fund and ETF distributions — income and capital-gains — whether paid out or reinvested, feeding the combined dividend calendar and yield-on-cost view.
What does not come across: Vanguard 401(k) and employer retirement plans administered by Vanguard's institutional side are generally not reachable through the retail brokerage connection; 529 education-savings accounts are excluded; and because Vanguard has no public developer API of its own, everything is read through SnapTrade's screen-backed connection, so the depth of historical transactions can be shallower than a broker with a true API. Real-time intraday quotes are never pulled — values are delayed.
Sync runs three times a day and position values refresh about every 30 minutes during market hours. StackViewer is not a real-time tool and is not built for day trading.
What Vanguard's own reporting doesn't show you
Vanguard's Personal Rate of Return is genuinely good, but it has one requirement that trips people up: it needs a minimum of 13 months of tracking history before it will calculate a figure at all (per Vanguard's own Performance help page, as of 2026-09-10). If you opened the account this year, added a new fund, or transferred assets in, you can be staring at a blank or partial return for over a year. StackViewer computes a money-weighted and a time-weighted return from your transaction history the moment it syncs, so you are not waiting on a 13-month clock — and it does it across your Vanguard and non-Vanguard accounts at once.
The bigger gap is that Vanguard shows you what happened, never why. It will tell you a fund returned 9% and that you are up on the year. It will not tell you that you sold an international fund in a panic three weeks before it recovered, that you have quietly drifted from a 60/40 to a 72/28 allocation, or that your one impulsive single-stock buy is dragging your Sharpe ratio down. StackViewer adds 15+ risk metrics — Sharpe, Sortino, Alpha, Beta, Max Drawdown, Value at Risk — and lets you tag each trade with a reason, conviction level and emotion, so over time you can see which of your decisions actually pay off and which are just noise you would be better off automating.
Also use Trading 212?
This is the exact pairing StackViewer was built for. Vanguard is where US investors park the boring, brilliant core — broad index funds bought and held for decades — while Trading 212 is where a lot of the same people run the active side: individual stocks, pies, and shorter-horizon bets. The two apps report completely differently and never combine, so your "real" performance and risk are split in half. Connect both and StackViewer produces a single time-weighted return across the two accounts, a combined diversification score, and one dividend calendar — rather than two apps you mentally add together.
How the combined multi-broker view works →
Is it safe to connect Vanguard?
The connection is read-only OAuth through SnapTrade. You log in on Vanguard's own site — StackViewer never sees your credentials and never stores them. The token that comes back can read positions and history and nothing else: StackViewer cannot place a trade or move a dollar, and no trading permission is requested at any point. In fact SnapTrade's Vanguard integration is read-only by design and does not support order placement at all (per SnapTrade's Vanguard integration page, as of 2026-09-10). You can revoke access from inside Vanguard whenever you want.
Data is encrypted with AES-256 at rest and TLS 1.2+ in transit, authentication runs on AWS Cognito with optional TOTP MFA, and you can export everything to CSV or delete your account at any time. Full detail on the security page.
Which other brokers can you connect?
StackViewer supports 31 brokers. Search for the others you use:
Frequently asked
- Is it safe to connect Vanguard to StackViewer?
- Yes — read-only OAuth through SnapTrade. StackViewer never sees your Vanguard credentials and cannot trade or move money. Revoke it from Vanguard in one click.
- Can StackViewer place trades on my Vanguard account?
- No. The token is read-only and trading permission is never requested. SnapTrade's Vanguard integration does not support order placement at all.
- How often does Vanguard data sync?
- Three times a day, with position values refreshed roughly every 30 minutes during market hours. It is not real-time.
- Is the Vanguard integration free?
- Yes, on the free plan, with no credit card.
- What Vanguard data does StackViewer import?
- Your fund and ETF positions with quantities and cost basis, your transaction history including buys, sells, dividends and reinvestments, and your settlement-fund cash balances. Vanguard has no developer API of its own, so all data is read through SnapTrade's screen-backed connection.
See it working before you connect anything
The live demo is a real portfolio with six months of history and every analysis screen populated. No signup, no email, no broker connection.
See the live demo or connect Vanguard freeNo credit card · Read-only access · Free forever plan
StackViewer is not affiliated with, endorsed by, or sponsored by Vanguard. Vanguard and its logo are trademarks of their owner. Broker connectivity is provided through SnapTrade and the available data depends on what Vanguard exposes; details verified 1 June 2026 and subject to change. Not financial advice.