How about leaving the personal stuff out of it, if you can?
Re: “no loss is incurred until an investment is sold”
Try buying something for say, $1M only to have it drop in value to say, $100k and telling your bank manager that your it’s all good and you still have assets of $1M because you paid $1M for it!
And see if he/she will value the asset at $1M or $100k
When related to shares, margin calls come to mind!