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stock-portfolio-tracker

A stock portfolio tracker maintains a watchlist of equities you follow and a holdings table that multiplies your share count by current price to show position value, gain/loss vs cost basis, and total portfolio value. The ZTools Stock Portfolio Tracker runs entirely in the browser, supports manual price entry or public-API pulls, persists your watchlist and holdings locally, and is for educational and personal-record use only — actual brokerage statements, tax-lot accounting, dividend reinvestment, and corporate actions are out of scope; never substitute calculator output for an authoritative broker statement when filing taxes or making transaction decisions.

Use cases​

Quick P&L glance​

See total gain/loss across all positions in 30 seconds without opening every brokerage tab.

Watchlist for ideas​

Track 10–20 tickers you are researching. See price changes; do not act on them without further analysis.

Educational tracking​

New investors learn how prices move and how percentage moves affect dollar P&L on different position sizes.

Pre-tax ballpark​

Year-end check: total portfolio gain. (Real tax requires lot-level accounting from your broker.)

How it works​

  1. Add tickers — Type the symbol (AAPL, MSFT, VTI). Watchlist saves locally.
  2. Pull or enter prices — API mode pulls from a public quote endpoint. Manual lets you paste a snapshot.
  3. Add holdings (optional) — Per ticker: shares owned + cost basis (average buy price).
  4. Compute P&L — Position value = shares × current price. Gain = (current − cost) × shares. Percentage gain = gain / (cost × shares).
  5. View totals — Grand totals across all positions: cost, value, gain, percentage gain.

Examples​

Input: Watchlist: AAPL, MSFT, VTI

Output: Three rows with live prices and 24h change

Input: Holdings: 100 AAPL @ $150 cost, current $180

Output: Position $18,000 · Gain $3,000 (+20%)

Input: Portfolio with 5 stocks

Output: Per-row + grand total: cost basis, current value, total gain, total %

Frequently asked questions​

Does it replace my brokerage account?

No. Brokers handle real money, lot-level cost basis, dividend reinvestment, corporate actions, tax forms. The tracker is a personal display tool.

Are dividends counted?

No by default — only price-change P&L. For total return, manually add dividend totals to the gain field.

How does it handle stock splits?

It does not — after a split, manually update share count and cost basis to reflect the new structure. Brokers handle this automatically.

Can I export to a spreadsheet?

Yes — CSV export of watchlist + holdings + current values.

Are prices real-time?

Public APIs are usually 15-min delayed for free tiers. For trading-grade real-time data, use a brokerage app.

What about ETF / mutual fund tracking?

ETFs work the same as stocks — single ticker. Mutual funds price once daily after market close, supported via the same flow.

Tips​

  • Use as a quick-glance overview, not for trade decisions.
  • For taxes, get year-end statements from your broker — they are the authoritative source.
  • Update cost basis when you make new purchases; otherwise the gain calculation becomes meaningless.
  • Diversify — single-ticker portfolios concentrate risk regardless of how good the company looks.
  • Avoid reacting to daily noise — long-term P&L is what matters; daily moves are mostly noise.

Try it now​

The full stock-portfolio-tracker runs in your browser at https://ztools.zaions.com/stock-portfolio-tracker — no signup, no upload, no data leaves your device.

Open the tool ↗

Last updated: 2026-05-05 · Author: Ahsan Mahmood · Edit this page on GitHub