1099b shows date of sale of stocks and proceeds. but does not show date acquired and cost basis. Also, box 5 states non-covered and X (unknown holding period). Problem is I bought company A years ago and 3 years(2019) ago they were acquired by another company. This company gave me x amount of stock in the new company. Last year(2022) I sold stocks of the new company three different times. Question is what date to use for when the stock was acquired and the cost of the stock.
