Hello htrumbo2,
Thank you for joining us today !
The IRS is treating Nadax Options as Section 1256 investments and Straddles and to be reported on Form 6781.
According the the Nadex Website, you should receive a 1099-B Annually to assist you in reporting your sales, etc.
For tax purposes, every Section 1256 gain or loss is treated as being 60% long term and 40% short term, no matter how long own it.
This TurboTax article on Section 1256 Contracts & Straddles will go into further explanation.
Good luck in your future trading!