Thanks to a Series B funding round, real estate startup Cadre has just raised $50 million. The online investment portal was co-founded by CEO Ryan Williams, who's worked at Blackstone and Goldman Sachs. Joshua Kushner of Thrive Capital, along with his real estate developer brother Jared Kushner, are investors and strategic advisers.

Cadre initially raised $18.3 million in a Series A round last year, which was led by Thrive And General Catalysts. The company has gotten backing from investors such as Yuri Milner, Goldman Sachs, Founders Fund, Alibaba Chairman Jack Ma, the Ford Foundation, and Khosla Ventures, among many others.

Since 2014, Cadre has been keeping things under wraps, only promoting itself to a selected group of investors like institutions, foundations, endowments and individuals with high net worth.

No one really knows how Cadre works, but are left with only a brief yet vague idea. The New York Post reports:

"While Cadre has been tight-lipped about how it works, the startup bills itself as a matchmaker that ensures clients are paired with the right real estate deals using proprietary software and its own due-diligence staff."

Since real estate is a "high touch" investment, the due diligence on both parties is essential to Cadre's balance of exclusivity and quality, in addition to "a walled-off website" that requires an invitation and vetting for entry, said Williams.

"Pristine sponsorship and great product - that is the mantra we have established," Williams proclaimed. "And we also look to ensure we are confident with the product. The technology platform is an element we bring to complement the investment experience."

Williams also noted that the startup's investors have shelled out "hundreds of millions" of dollars for deals around the country that are being offered by top sponsors on the Cadre platform.

"We needed a platform to connect investors with institutional quality real estate outside the prevailing fund model," Williams noted. "I could more efficiently connect investors to quality investments."