There are a few posts in SO that point to sources for downloading historical stock quotes, but they all refer to the currently listed symbols. The resulting data set suffers from retention avoidance. Is there any source of all historical data, including sensitive companies, preferably for free / cheap? I have found several sources, but usually they are hundreds of dollars or more, require installation using any Windows client software, or simply on fragmentary websites. (The data at the end of the day is in order - I am sure that the request for an intraday application / request is too much.)
Where do these data resellers get their data from? What is the original source data archive? (Some of these datasets date back to the 50s, so I don’t think the answer is “they just record it themselves.”) Do they cut transactions with exchanges / do exchanges / sell it? Is there data in any public records? Thank!
Norgate Investor Services is the cheapest I have found, but it will run you hundreds of dollars (but less than 1000). Their source is Standard and Poors.
QuantQuote , //, $$. S & P500. Yahoo , .