You don't need to enter each transaction. You can enter one transaction for the short term losses, and one transaction for the long term losses. Instead of an acquisition date, use "Various". For the disposition (sale) date you should use the date you became aware that the company had filed for bankruptcy (i.e. the date you knew the stock was worthless).
You are correct, you will enter as Long/Short Term - did not receive Form 1099B.
The description you put in your question "50 shares of ABC company - Worthless" is fine.
You don't need to mail anything.
**Say "Thanks" by clicking the thumb icon in a post
**Mark the post that answers your question by clicking on "Mark as Best Answer"
