The pair met in late 2017 shortly after her relationship with Silicon Valley tech manager William Knight ended.
“Emma and Chord kept quiet about their relationship at first but they really hit it off,” a source told The Sun.
“They spent a lot of time together in Los Angeles and were photographed quite a bit just a couple of months ago.
“But things just haven’t worked out between them and they are both now single again.”
“It was never going to be a long-term thing,” another source told People.
The star is yet to confirm the news but has unfollowed him on Instagram, which is 2018 is as good as done.
The Harry Potter star opened up last year about struggling to keep her personal life private.
“I want to be consistent: I can’t talk about my boyfriend in an interview and then expect people not to take paparazzi pictures of me walking around outside my home,” she told Vanity Fair.
“I’ve noticed, in Hollywood, who you’re dating gets tied up into your film promotion and becomes part of the performance and the circus.
“I would hate anyone that I were with to feel like they were in any way part of a show or an act.”