My wife worked for a company for many years with a monthly stock purchase plan, so stock was purchased every month. She changed jobs, and I transferred these stocks from Computershare to Etrade, and then sold the entire lot soon thereafter. The 1099-B I received from Etrade had 0 cost basis, and 1/1/1900 as the date acquired. I have the correct cost basis that I've entered. What do I enter for date acquired since it was many many dates.
