From instructions for 4684, Losses You Can Deduct
For tax years 2018 through 2025, if you are an
individual, losses of personal-use property from
fire, storm, shipwreck, or other casualty, or theft
are deductible only if the loss is attributable to a
federally declared disaster (federal casualty
loss). See Pub. 547 for more information.

for investment loss see the complete instructions

https://www.irs.gov/pub/irs-pdf/i4684.pdf