Koch network - one of the brothers died 2019.
https://www.msn.com/en-us/news/politics/koch-network-to-back-alternative-to-trump-after-sitting-out-recent-primaries/ar-AA177NHe
https://www.nbcnews.com/news/us-news/david-koch-billionaire-conservative-activist-philanthropist-dies-79-n1045696