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Sourcing Historical Data

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Because Portblend operates on a privacy-first, local analysis model, we do not store or license active market databases. You bring your own historical data.

While platforms like Yahoo Finance have restricted direct downloads, getting clean historical data for mutual funds, ETFs, or index series is still straightforward and free. This guide covers the best reliable sources for non-technical users.

1. US Equities, Stocks, & ETFs: Nasdaq

For any asset traded on a US exchange (like SPY, QQQ, VTI), Nasdaq.com provides free, unrestricted historical data downloads.

Step-by-Step:

  1. Go to Nasdaq.com and search for your ticker symbol (e.g., SPY).
  2. On the asset’s quote page, look at the left sidebar menu and click Historical Data.
  3. Select your desired time frame (e.g., 5 Years or 10 Years).
  4. Click the Download Data button to save the CSV file directly.

Note: Nasdaq’s CSV includes multiple columns (Open, High, Low, Close) and formats prices with a dollar sign (e.g., $393.45). You can upload this file directly to Portblend — our parser automatically identifies the correct columns, ignores extra fields, and automatically strips out currency symbols ($) and commas for you.

2. Global Funds, Crypto, & Indices: Investing.com

If you are looking for international mutual funds (UK, Europe, India, Asia), cryptocurrencies, or global stock indices, Investing.com is the easiest source.

Step-by-Step:

  1. Go to Investing.com and search for your fund, index, or asset.
  2. Under the main asset profile name, click the Historical Data tab.
  3. Select the date range you want to analyze and click Apply.
  4. Click the Download Data button on the right side above the data table to get your CSV file.

3. Interest Rates, Cash, & Commodities: FRED (St. Louis Fed)

For macroeconomic benchmarks (like the risk-free rate, 10-year Treasury yield, inflation indices, gold, or oil prices), the Federal Reserve Economic Database (FRED) is the gold standard.

Step-by-Step:

  1. Go to FRED.
  2. Search for the benchmark asset you need (e.g., search Gold Fixing Price or 3-Month Treasury Bill).
  3. Click the red Download button in the top right corner of the chart.
  4. Select CSV (data) to save the historical series.

4. The Google Sheets Shortcut (For copy-pasted data)

If a website displays historical prices in a table but does not have a download button, you can easily convert it using Excel or Google Sheets.

Step-by-Step:

  1. Click and drag to highlight the table rows on the website.
  2. Press Ctrl + C (or Cmd + C) to copy.
  3. Open a blank spreadsheet and press Ctrl + V to paste.
  4. Keep only two columns: one for Dates and one for the Closing Price / NAV.
  5. Go to File > Download > Comma Separated Values (.csv).

You now have a clean, validated CSV file ready to drop directly into Portblend’s Prepare Data tab.