"Stooq now requires API key - Documentation update needed"

[smorelosmx]

As March 2026, Stooq requires an API key for data downloads.

Problem

pandas_datareader.DataReader(ticker, 'stooq', start, end)
now fails with ParserError because Stooq returns an HTML page
with instructions to request API key instead of CSV data.

Solution

Users must:

1. Get API key from: https://stooq.com/q/d/?s=spy.us&get_apikey
2. Use custom function with requests library (code example)

Suggested fix

Either update DataReader to support apikey parameter, or
document this breaking change in the README.

Python Code to test Stooq and get instructions :

import requests
url = "https://stooq.com/q/d/l/"
params = {
"s": "spy.us",
"i": "d"
}
r = requests.get(url, params=params, timeout=10)
print(r.status_code)
print(r.text[:500])