@stan101 I am not certain if I can be of any help; I have lost...

@stan101 I am not certain if I can be of any help;
I have lost lots of money in the 2008-10 downturn - was heavily invested in a range of stocks - then began trading and eventually selling in panic - (I lost $90 000 but had funds left) - I slowly and cautiously re-entered the market many years later - (and have been doing a carry-over of my big loss year after year) - have made small gains, not big ones and am entering my now diminishing loss yearly. I am doing it all with the vetting of a proper accountant but was already retired in 2009.
So, my experience, yes you can write it off - not in one hit, just a carry-over figure year after year.
It's a sad lesson to read this - conclusion: never put your eggs in one basket.
P.S, the people running this show and many others on other companies just mine the s.h,'s pockets and nothing else - what a life! SO; buyer beware!
And - incidentally - I I had kept my portfolio then, I would - over time - only have made some losses on some but big gains on the others - probably come out even. So maybe just holding on is the best policy here too.
You never know - climate change is really hitting hard in Europe this year - last night I spoke with someone living in country Central Europe and the weather is hot, totally unpredictable even on an hour-to-hour basis. They also travel a fair bit - and same diagnosis; climate change is here to stay.
Taurisk