UPDATE 1-Robinhood to buy fintech firm Say Technologies for $140 mln

(Adds details on Say's business, background)

Aug 10 (Reuters) - Robinhood Markets Inc said on Tuesday it would buy fintech startup Say Technologies for $140 million in an all-cash deal, weeks after the online brokerage's stock market listing.

New York-based Say, founded in 2017, has built a communication platform that crowdsources questions from retail investors and allows them to interact with the companies they invest in during annual meetings, earnings calls and other events.

Say also offers shareholders proxy-voting and polling services. Its platform has been used during Tesla Inc's earnings calls, according to media reports.

"Say was built on the belief that everyone should have the same access to the financial markets as Wall Street insiders," a blog post from Robinhood said.

With a marketing mantra of "democratizing finance", Robinhood has sought to win over retail investors. In May, the company unveiled a new platform to allow retail investors the opportunity to snap up shares in initial public offerings.

The company had an underwhelming market debut late last month, but the stock has since seen a wild rally and was up nearly 50% from its IPO price as of last close.

(Reporting by Niket Nishant in Bengaluru; Editing by Shinjini Ganguli)