Holt has a friendly rivalry with Batman, his opposite number in the Justice League of America (in his identity as Bruce Wayne, Batman owns Holt's business). Holt has encountered Sloane twice through time travel, with Sloane expressing pride in having so worthy a successor. Holt has been noted as the most intelligent member of the JSA in its history, surpassing his predecessor. He is also known as the third-smartest person in the world, and this notion now appears to be widespread within the DC Universe.