Historical data do not include dividends (so adjusted price is incorrect) for all all/most stocks/etfs
Historical data is not updating/including dividends for all stocks/etfs since december 18 (for some stocks even earlier. e.g.: itub dividend on december 15 does not show). So adjusted prces since then is not proper either.
44th
ranked

-
Stephen Share commented
I have noticed this as well and I have no idea how to point this out to Yahoo with all their convoluted forums