Is the national average negative?

Maybe if you exclude the 1%, who probably hold half the retirement savings, but obviously are vastly in plus on the total.

Nah, some of them can swim

More likely a typo, I think. From the report’s executive summary:

Working individuals who have positive DC savings had median savings of $40,000 in December 2022. Across all workers, including those with no savings, the median amount saved was only $955.