May 19 (Reuters) - Polymarket on Tuesday launched prediction markets tied to the performance of private companies through an agreement with Nasdaq Private Market, marking a first for the rapidly growing sector, it said.

Here are some details:

o Prediction markets allow users to trade on the outcome of future events, with prices reflecting the perceived probability of those outcomes.

o Polymarket said the new events could include private company milestones such as valuation, IPO timings and secondary market activity.

o Prediction markets have grown popular as users increasingly trade on the outcomes of events ranging from elections to cryptocurrencies.

o Polymarket's new offering also creates an additional price discovery tool for institutional investors, the company said.

o It added that the Nasdaq Private Market will serve as the resolution data provider for private company markets on Polymarket.

o The launch comes as companies stay private for longer. Several startups have reached valuations comparable to companies in the S&P 500, drawing growing investor interest in private markets.

o Polymarket said nearly 1,600 unicorns globally, or startups valued at more than $1 billion, now account for over $5 trillion in cumulative value.

(Reporting by Manya Saini in Bengaluru; Editing by Devika Syamnath)