Jon Hamm – aka the show's enigmatic Don Draper – joined fellow cast mates including his on screen ex wife Betty Draper, played by January Jones, in ringing the opening bell to get trading underway.
With her hair loose around her shoulders and wearing a smart trouser suit, Christina Hendricks' look was far removed from that of from her on screen, persona, Joan Holloway, who favours form-fitting dresses and glam up'dos.
Making up the group were Kiernan Shipka, who portrays January's on-screen daughter Sally Draper, and John Slattery, who plays silver fox Roger Sterling.
The fifth season premieres on March 25 with a two-hour episode.
It's been 17 months since the series was last on screens, and John says that the time away "reenergised" the cast members.
"We had been gone so long and everybody did their own projects, had babies, etc," he said – referring to January's new arrival, five-month-old baby Xander.
"I was also directing the first episode when we came back so that was fun to rally around. Whatever momentum was lost was quickly regained because we were so excited.” Fans are on tenterhooks waiting to see what happens in the new season.
At the end of the fourth installment, Don proposed to his secretary Megan after a whirlwind romance.
Meanwhile his company Sterling Cooper Draper Pryce was floundering after losing their biggest client.
Office manager Joan becomes pregnant after a fling with Roger, while her husband is stationed in Vietnam.
But as to whether her secret gets out, viewers will just have to wait. When John was asked about what fans can expect, he gave nothing away.
"What we continue to attempt to do is tell the story," he tells The Daily Beast.
"And it’s a story that’s going to have an end, so this is the next chapter.
"Marriages have dissolved, people have died, people have succeeded and failed, and it’s all served to move the characters' stories along in this rich and fascinating environment."