I need historical data of currency exchange rates for my gooogle sheet and GOOGLEFINANCE function is just what i need. Here is the sheet with GOOGLEFINANCE data I copied from my project: https://docs.google.com/spreadsheets/d/15cFmrS2IL6QZMJORCJxU16QtWQ-2hFNLORgM5pEgY_E/edit?usp=sharing
The problem is that sometimes (pretty often actually) GOOGLEFINANCE function crashes and returns error breaking the whole project: that's how it looks when it crashes
It returns to normal after a while but it's really disturbing.
I couldn't think of a good way to work around that glitch so I'm asking for your help.
I thought about making cells with the following logic: IF GOOGLEFINANCE value is not blank then copy it ELSE keep old value making GOOGLEFINANCE return persistent but I'm not sure it's possible to do with Google Spreadsheets formulas.
For example above if we want to make L4 cell to contain persistent value of C4 cell, I want L4 formula to be like:
=IF(ISBLANK(C4),L4,C4)
but then cell will refer to itself which is not allowed.