title: Downloading complete historical stock data including delisted companies?
body: <ol>
  <li><p>There are several posts on SO that point to sources for downloading historical stock quotes, but these are all for currently listed symbols. The resulting dataset suffers from survivorship bias. Is there any source of all historical data, including delisted companies, preferably for free/cheap? I've found a few sources, but they're usually hundreds of dollars or more, require installing using some Windows client software, or just are on sketchy-looking websites. (End-of-day data is fine - I'm sure asking for intraday bid/ask is too much.)</p></li>
  <li><p>Where do these data resellers in turn get their data from?  What is the original source archive of data?  (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 deals with exchanges / do the exchanges have/sell this?  Does the data exist in any public records?  Thanks!</p></li>
  </ol>