WaPo reports that the FBI found … oh, here it is in their own words—

That review has not found any apparent business advantage to the types of classified information in Trump’s possession, these people said. FBI interviews with witnesses so far, they said, also do not point to any nefarious effort by Trump to leverage, sell or use the government secrets. Instead, the former president seemed motivated by a more basic desire not to give up what he believed was his property, these people said.
…
The people familiar with the matter cautioned that the investigation is ongoing, that no final determinations have been made, and that it is possible additional information could emerge that changes investigators’ understanding of Trump’s motivations. But they said the evidence collected over a period of months indicates the primary explanation for potentially criminal conduct was Trump’s ego and intransigence.

Funny how that leaked the week after the midterm elections.