A small office building in Harlem just became the first lone edifice in New York City to take itself public.

The otherwise unassuming, 18,759-square-foot retail and office property at 286 Lenox Ave. – whose three tenants include a Wells Fargo branch near the corner of West 125th Street – quietly began trading on the over-the-counter markets last week.

It’s the first time that a building in New York has been securitized and offered to all investors via the secondary market, according to Jesse Daugherty, co-founder and co-CEO at Lex Markets, which handled the offering.

“The stock has been trading since Wednesday, but we haven’t publicized this at all beyond notifying our users that trading was open which we had a duty to do,” Daugherty told The Post. “We … decided to close the IPO so investors could start trading.”

On Monday, the thinly traded stock, which trades under the ticker symbol TESLU, was recently at $250, giving the building a market capitalization of more than $11 million.

After being offered at $250, the stock climbed as high as $255 on Thursday and sank to $241 on Friday before returning to $250 as of Monday afternoon. Just 57 shares had traded hands as of early Monday afternoon out of 7,133 shares outstanding.

According to the company, owners of commercial real estate can use the Lex platform to raise capital by securitizing a portion of their property. This allows them to recapitalize their equity and take out cash while still receiving management fees. At the same time, members of the public can invest in single assets without being accredited investors.

Meanwhile, shares in a 600-space parking garage in Portland, Maine, that went live in March 2021 under the ticker GWYGU are also down after trading at a high of $253.60 right after it went public to a current price of $241. Lex is also preparing to float shares for an apartment building with retail in Seattle.