Portfolio Tracker

How to use Portfolio Tracker

Add symbol, amount, and cost basis per lot. Holdings stay in localStorage. Totals show portfolio value, aggregate cost, P&L, and ROI using live CoinGecko USD marks that refresh about every minute (paused when the tab is hidden).

Example: a two-coin portfolio (illustrative prices)

You hold 0.5 BTC bought at $40,000 and 10 ETH bought at $2,000. Prices below are examples; the tracker loads live ones.

1. BTC: value 0.5 × $65,000 = $32,500, cost 0.5 × $40,000 = $20,000
2. ETH: value 10 × $3,000 = $30,000, cost 10 × $2,000 = $20,000
3. Portfolio value = $62,500; cost = $40,000
4. Profit = $22,500; ROI = $22,500 ÷ $40,000 = 56.25%

The portfolio is worth $62,500 on a $40,000 cost, a 56.25% gain. Everything stays in your browser.

Formula & methodology

Position value = amount×spot. Cost = amount×costBasis. Portfolio PnL = Σ(value−cost). ROI = PnL/Σcost. Spots load through /api/prices with a 60s shared cache.

Track crypto portfolio P&L in your browser

Many portfolio apps demand email signup and cloud sync. CryptonicTools stores holdings only in your browser, which suits a personal watchlist or a shared laptop where you clear data when you are done.

Mark-to-market uses the same CoinGecko USD feeds as converter and price pages, so P&L stays consistent across the site. Add multiple lots of the same asset for separate cost bases. Remove rows when you sell.

There is no backup server. Use Export backup / Import backup in the tool to move a JSON file between browsers, or screenshot balances if they matter. Local-only storage avoids auth complexity and custodial risk.

Cost basis vs mark-to-market

Cost basis is what you paid. Mark-to-market is what the stack is worth now. ROI mixes both into one percentage so you can glance at performance without a spreadsheet. Separate lots keep different entries distinct.

If live prices fail, holdings still display but P&L may understate until Retry succeeds. That keeps your list intact instead of wiping the session.