She’s gone from Occupy Wall Street to occupying a job on Wall Street.

Down-on-her-luck protester Tracy Postert spent 15 days washing sidewalks and making sandwiches at Zuccotti Park — then landed a dream job at a Financial District investment firm thanks to a high-powered passer-by who offered her work.

“I never thought I would be doing this,’’ Postert admitted to The Post.

The Upper West Sider, who has a Ph.D. in biomedical science specializing in pharmacology, was unemployed and had all but given up on finding work in her preferred field of academia when she joined the movement in October.

She held signs that read, “Reagan sucks,” and, “I’ll vote after the revolution.”

But she said she still needed to get a real job. So she made a new sign.

On the front, she wrote, “Ph.D. Biomedical Scientist seeking full time employment,” and on the back, “Ask me for my resume.”

It caught the eye of Wayne Kaufman, chief market analyst for John Thomas Financial Brokerage. The exec wasn’t looking to hire, but he took Postert’s résumé anyway.

That was Oct. 22, Postert’s Day 10 as an Occupier.

The next day, Kaufman, impressed by her CV, sent her an e-mail asking if she’d like to come for an interview.

It wasn’t far — only two blocks from Zuccotti Park at 14 Wall St.

“I had been unemployed for so long, I thought why not?” said Postert, adding that she is in her 30s and has no background in finance or business.

Her last paying job was as a lab assistant at Touro College making $2,500 for the one semester she worked there, she said.

Kaufman offered her a job as a junior analyst evaluating medical companies as potential investments.

Postert said the decision to accept was painful.

But practicality won out.

The starting salary as a junior analyst is near minimum wage, but in time, she can earn a cool six figures, assured Kaufman.

Postert has now just completed her third week as a Wall Street geek.

She’s already studying for her exams to be a certified financial analyst.

“I want to get a perfect score,” she said.

Life has definitely changed for the former Occupier.

She’s in the office by 8 a.m., and she still has to get used to Kaufman’s rallying cry of “Go! Go! Go!” blaring over the speakers in the morning.

CEO Thomas Belesis said he believes Postert will be a great asset.

“She was ranting about Wall Street, and now she’s working on Wall Street. Banks are not so bad. I hope we have opened her eyes,” he said.