Shares of drug research firm PPD Inc. rose 14.8% in their Nasdaq debut on Thursday, marking a stellar stock market entry for the second $1 billion-plus flotation of the year.

Shares (PPD) opened at $31, giving the North Carolina-based company a market valuation of $10.52 billion.

It is the biggest U.S. IPO of 2020 so far, following the blockbuster listing of Reynolds Consumer Products last week.

The company priced its offer of 60 million shares at the top end of its targeted range of $24-$27, raising $1.62 billion on Wednesday.

The Wilmington, North Carolina-based company posted a profit of $47.9 million in the nine months ended Sept. 30, compared with $59.7 million, a year earlier.

PPD, which provides drug research services to pharmaceutical and biotechnology companies, plans to use the IPO proceeds to pare its debt.

"It's a pretty steady business, and even with that debt, I have a company that's got positive cash flow and free cash flow. So it's able to handle the debt," said Kathleen Smith, principal, Renaissance Capital, provider of institutional research and IPO ETFs.

Private equity firms Carlyle Group and Hellman & Friedman have owned PPD since 2011, after they took the company private in a $3.9 billion leveraged buyout.

The two firms will retain significant voting power after the flotation, with H&F retaining a 57% stake, and Carlyle owning nearly 24% of all outstanding shares.

Barclays, J.P. Morgan, Morgan Stanley and Goldman Sachs & Co were the lead underwriters for the IPO.