YF doesnt have some data in a stock I follow (there are a bunch of 'null' rows for some reason). The data exists but I dont know of a site that will let you download it so easily. Is there one?
One of our newest sponsors is called Polygon.io and they offer both real-time and downloadable historical data for all 24,000+ stock symbols, and you won't have to deal with null rows.
I downloaded it off Tiingo and the data has the same exact flaw, looks like their business model was to download everything Yahoo has and charge for it
Even IB data starts from Oct 28, the company announced uplisting just that month so most likely it wasn't traded on an exchange until that date, uplisting dates are often postponed. You're probably comparing to your broker's data which doesn't distinguish between listed and OTC.
I was able to obtain the data from Bigcharts historical quotes function, but i had to do it day by day
Bigcharts has their own method which IMO is wrong as the CUSIP changed. Their website: As of October 7, Anavex common stock will trade under the ticker symbol AVXLD for a period of 20 business days. After that time or earlier once NASDAQ approves the uplisting requirements, the “D” will be removed and our Company’s symbol will once again be AVXL. A new CUSIP number will be assigned to the Company’s common stock as a result of the reverse split.