Sounds like you own 1000 shares of Altaba. Their initial distribution is $51.50 in 2019. Check this: https://www.irs.gov/publications/p550
specifically this section "Liquidating Distributions"
I am no expert but I think you have to report your 2019 capital gain now. I'm in the same situation but my initial distribution is several thousand below my cost basis. It is a loss. I must wait until final distribution before filing capital loss.
