COMC Web Portfolio Value Estimator

WHAT IT DOES

This tool helps you track and analyze your COMC portfolio value. It scans portfolio pages for card data—card names, players, sets, serial numbers, purchase prices, current asking prices, and quantities. The panel displays total portfolio value, average return per card, and a breakdown of gainers and losers. Best and worst performing cards are highlighted with percentage change indicators. Cards with significant price movement are highlighted with color coding—green for gainers, red for losers. Quick "View" buttons open COMC search results for cards, and "Export CSV" copies all portfolio data to your clipboard. A summary shows total gain/loss, average gain, and counts of winners and losers.

WHERE IT RUNS

The script activates on COMC pages (comc.com), including portfolio views, inventory pages, and card listings. It automatically detects card data using multiple extraction strategies that work across different COMC layouts. The panel appears as a draggable overlay that stays accessible as you browse your portfolio.

HOW TO USE

Navigate to your COMC portfolio page. The panel will appear showing total portfolio value and summary statistics. Select your preferred currency (USD, EUR, GBP) for price display. Toggle "Zero on/off" to show or hide zero-value cards. Set the "Threshold %" to control when cards are highlighted as significant gainers or losers (default 10%). Set the "Refresh (s)" input to control how often the script checks for updates (default 60 seconds). The "Scan" button manually refreshes the data, and "Export CSV" copies all portfolio data to your clipboard. Click the "View" button on any card to search COMC for that card. The best and worst performers are shown at the bottom of the panel.

THE TECHNICAL MECHANISM

The script employs a multi-strategy DOM extraction approach for COMC's portfolio interface. It first attempts structured selectors targeting known class names like .portfolio-item, .card-item, and .inventory-item, then falls back to heuristic detection of card containers based on content patterns including currency symbols and card-related keywords. Card names are extracted from dedicated name elements or by parsing the first non-numeric text line. Player and set information are extracted from dedicated elements. Purchase prices are extracted using regex patterns for "purchase" followed by currency amounts. Current asking prices are extracted from "asking" patterns or general price matches. Quantity is extracted from qty patterns. Gain/loss is calculated as (askingPrice - purchasePrice) * quantity. Gain percentage is calculated as (gainLoss / (purchasePrice * quantity)) * 100. The highlight threshold controls when cards are color-coded as gainers or losers. The auto-refresh uses setInterval with a user-configurable interval, and a MutationObserver watches for page updates. All settings are persisted using GM_setValue.

THE PANEL

The panel is fully draggable by its header and remembers its position on the page across sessions. It can be collapsed to a small bubble using the minimize button, then restored by clicking the bubble. The panel resizes automatically to fit its content and can be closed with the Escape key or by clicking the close button. The panel's position and state persist globally, so it returns to the same location on subsequent visits.

PLEASE NOTE

Requires the free BotGentz extension to run. COMC may update its site structure, which could affect the script's ability to detect portfolio data — updates will be released as needed. All portfolio data is read from the page and displayed locally; nothing is transmitted externally. The script reads data from the visible page and does not access any data beyond what is visibly presented. The script does not modify your COMC account or listings. Gain/loss calculations are based on purchase prices and current asking prices displayed on the page. The CSV export copies data to your clipboard for personal use. This tool is for informational purposes only and is not affiliated with COMC. Portfolio values are estimates based on asking prices and may not reflect actual sale prices.