After completing all three norms required for the title at the Foxwoods Open in January 2014, Saint Louis GM Invitational in May and Washington International in August 2014 at age 13 years and 7 months, he then completed the final requirement for the title by reaching over a FIDE rating of 2500 during the Saint Louis GM Norm Invitational tournament, which he won convincingly with the score of 7½/9 points.

[8] Sevian shared fifth place in the US Chess Championship 2015, beating Wesley So, a world top ten ranked player, and drawing with Hikaru Nakamura as well as defending champion Gata Kamsky.

This performance earned him a spot in the Chess World Cup 2015, where he drew both classical games against Teimour Radjabov in the first round of the tournament but was eliminated in the rapid playoff.

In June 2017, Sevian won the American Continental Chess Championship in Medellín, Colombia, which in that year had assembled the best Grandmasters of the Western Hemisphere, scoring 8½/11 points with superior tiebreak.

Also in 2021, Sevian finished the United States Championship in the top three with the same score 6.5/11 as Fabiano Caruana and the eventual tie-break winner Wesley So, with a performance rating of 2747, higher than that of all the competitors.

His father, Armen, held the title of candidate master in Soviet Armenia before moving to the United States in 1996 for his PhD studies.