On 1/9/2018, Diane Feinstein released the transcript of the Senate interview of Glenn Simpson of Fusion GPS. You can download the original pdf transcript here or view the html version below.
On 1/18/2018, the House released the transcripts of their own interviews with Glenn Simpson. I've re-typeset these for clarity.
This is the transcribed interview of Glenn Simpson. Chairman Grassley and Ranking Member Feinstein requested this interview as part of the Senate Judiciary Committee's investigation of Fusion GPS's activities related to the dossier compiled by Christopher Steele, the Prevezon case, and the Magnitsky Act.