On my system, the values downloaded as Historical Values are wrong on the weekends for these stocks: GOOG, NDAQ, TRRKX. This started July 27 and continues.
Also, during the month of January of this year, the same problem occurred 3 times sporadically in NVDA, SPY, AMD, XLK.
This also occurred some times last year. In each case, on weekends, the value of the stock changed, up or down, to a specific value, then back to correct on Monday. In my case (but not in some others that had reported this), the weekend values are always exactly the same. This creates havoc, as you can imagine.
This has been reported before on the forums, as late as last month, with others reporting similar issues, only to have the thread closed without a solution.
Here is the downloaded pricing for GOOG:
Here are graphs for NVDA and GOOG showing the result of this problem:
This showed up as a 64% increase in 1 day! I almost bought a new Mercedes! Only to have to sell it 2 days later! :-)
Google, OTOH, showed a decrease on weekends to the same value each weekend.
Isn't it about time this kind of thing is fixed??? I like a few of the new features over the years, and realize you have to justify the yearly buying of the product, but the same problems and sluggishness have been there for many years, and that's never fixed.