A pair of Watertown biotechnology start-ups together raised more than $130 million through initial public offerings this week, a sign that the long-sluggish IPO market may be rebounding.
But investor appetite for the newly public companies diverged.
Shares of Enanta Pharmaceuticals Inc., which is developing drugs to combat the hepatitis C virus, climbed nearly 23 percent Thursday on the company’s first day of trading. But the stock price of Tetraphase Pharmaceuticals Inc., which is working on antibiotics to treat abdominal and urinary tract infections, edged up just 0.7 percent Thursday from the Tuesday offering price. The share price was unchanged Wednesday.
In the first days of trading, companies that go public are typically under a so-called quiet period imposed by federal securities regulators. A spokeswoman for Enanta said executives there were not available to discuss the IPO, while Tetraphase representatives did not return phone calls.
Michael Ringel, a partner and managing director for the strategy consulting firm Boston Consulting Group who specializes in biopharmaceutical research, said the pace of IPOs often tracks with that of mergers and acquisitions, which pick up at times when stocks are rising.
“We’re seeing a merger wave coming back to life, and we’re seeing the IPO market come back to life,” said Ringel, who said the trend extends to life sciences firms and other companies.
“There’s a general consensus we may be entering a more active capital markets phase.”
Enanta sold 4 million shares at $14 a share in its IPO, raising $56 million. The offering was managed by investment banks J.P. Morgan and Credit Suisse.
Enanta’s stock price advanced $3.18 to $17.18 a share Thursday on the Nasdaq market on a day US financial markets retreated broadly amid new worries over earnings and Europe’s financial health.
In its public offering, Tetraphase sold 10.7 million shares at $7 a share, raising $74.9 million.
That IPO was managed by the Barclays and BMO Capital Markets investment banks.
Tetraphase’s stock moved up 5 cents a share Thursday to $7.05 on the Nasdaq.Robert Weisman can be reached at email@example.com. Follow him on Twitter @GlobeRobW.