I’m trying to chart the price of General Motors stock (GM on NYSE) since 1920, from quotes in old online newspapers. However - there were unreported stock splits in the early days, and I’m trying to figure out what/when they were. There seems to be no info on the GM web site before 1989, and Google doesn’t seem to be any help.
So far - I seem to have found a 10 for 1 split sometime in 1920 (price goes from 300 to 30), and another split (2 for 1, or maybe 3 for 2) in 1929 (price goes from the high 100’s to around 100 - this was before the October “crash”).
The Center for Research in Security Prices (CRSP) at the University of Chicago Booth School of Business would have this information at least back to 1926 (I think) to the month, but not necessarily the day. I’m not sure how you’d get it from them though.
This site looks like it has data over the period you’re missing (look under the Data tab):
Cowles Data | Yale School of Management
The Wall Street Journal has a chart that looks like it goes back to 1920, but they don’t cite where they got the data.
It says they got it from CRSP which I already mentioned.
GM bottomed out at the newspaper-quoted $11 in 1933. Looking at the chart, it was close to zero in 1933 - meaning there must have been splits in later years. I’ll continue my search.