How Does the Mark-to-Market Rule Simplify or Complicate Tax Reporting?

It simplifies reporting by eliminating the need to track the holding period for short-term vs. long-term gains and by generally precluding the wash sale rule. However, it complicates matters by requiring the calculation of unrealized gains/losses at year-end and by potentially accelerating tax liability on gains that haven't been cashed out.

Is There a “Wash Sale” Rule Equivalent in Crypto Derivatives Trading?
How Does the Wash Sale Rule Differ for Stocks versus Section 1256 Contracts?
What Is the Primary Tax Benefit of the Wash Sale Rule Not Applying to Section 1256 Contracts?
Does Wash Trading Create Tax Liabilities for the Wash Trader?
How Does the Mark-to-Market Rule Simplify or Complicate Tax Reporting for Traders?
Is There a De Minimis Exception to the Wash Sale Rule for Small Traders?
What Is the Significance of the “Constructive Sale” Rule in Section 1256 Taxation?
What Is the Maximum Holding Period for a Short-Term Capital Gain?