How can I write off a worthless investment without a 1099-B? The company let you invest in shares of collectibles like baseball cards. But the company disolved in Dec.

When you get to the point that you are starting to enter the investment sale, choose 'Other' as the type of investment because that will indicate that you do not have a Form 1099-B.

A worthless investment may be deducted as a loss in the tax year that it becomes completely worthless.  This means that the corporation has filed for bankruptcy, has stopped doing business, and has no assets.

Entering the information for the worthless stock is the same process as entering any other investment sale, except for the following fields:  

• Your sales price will be zero
• Include the word 'worthless' in the description field
• Enter December 31st as the date sold

All other information will come from your records such as the cost basis and date acquired.

See the following TurboTax help article for guidance to enter investment sales:

Where do I enter investment sales?