[dsr_]

> Then there are pieces of data that should never change, like a company's CUSIP (essentially the primary key in a database of stocks).

I hate to break it to you, but tickers and CUSIPs do change.

The world of 'corporate actions' turns out to be a catchbasin requiring human intervention.

[gymbeaux]

Yeah fair enough. I see a ticker change somewhat often (eg ETH to ETD, FB to META), CUSIPs change much less often, but unlike tickers CUSIPs aren’t reused. A company’s CUSIP will always be their CUSIP, but it might not be their current CUSIP.