it seems to me that for CNDX.L (iShares NASDAQ 100 ETF USD Acc) Yahoo Finance shows incorrect historical prices.
If you check out https://finance.yahoo.com/quote/CNDX.L/history?p=CNDX.L you'll see that e.g. the open price on Jul 23, 2018 is $309.98 and then on Jul 27, 2018 it's $413.58. If you check the *Link Removed - See the community guidelines for more information.*, where supposedly the same market data is available you can see that the July 23 price was rather around $408, there is no such jump in reality (the prices shown by Yahoo before July 23 are all too low).
My hunch is that at one point between the dates the feed the data comes from changed its currency from GBP to USD (the ETF is actually traded in USD with this ticker) because GBP 304 was suspiciously around USD 408 at that time.
Could somebody from the technical team check this please?
@Piedone - Thanks for the report. I see the data discrepancy you are referring to when comparing the data to other historical data sources. I have submitted this to engineering for investigation and correction.
Thank you for the additional ticker experiencing this problem. I have added this fund to the open ticket we have for this issue.