NEW YORK – Shares of Castlight Health Inc. surged in their first day of trading, after the health-plan software maker’s initial public offering raised more money than expected. The San Francisco company’s stock more than doubled to $37.50, up 134% from the $16-a-share offer price available to buyers in the IPO – typically large investors like mutual funds and hedge funds.

At its opening price, Castlight carried a market value of about $3.2 billion, despite it having posted just $13 million in revenue last year and, according to analysts’ estimates, no profits yet in sight.

Castlight’s provides its offering over the Web to subscription-paying customers – corporations looking to lower costs and improve efficiency in employee healthcare plans. The company provides data on the cost and quality of medical services like doctor visits and lab tests.

“It’s a real solution to a huge intractable problem that has defeated the best efforts of the self-anointed geniuses in Washington,” Rett Wallace, cofounder of Triton Research told the Wall Street Journal. Triton Research analyzes private tech, media and communications companies.

Castlight listed on the New York Stock Exchange under the symbol “CSLT.” Goldman Sachs Group Inc. led the IPO with Morgan Stanley.

Castlight was founded in 2008 by three health tech executives – including Todd Park (pictured), the United States’ current chief technology officer. The company gained attention last year after it closed $100 million in funding and announced major customer wins, including organizations like Honeywell, Life Technologies, and Indiana University. The company reported 2013 revenue of $13 million, up from $4.2 million a year earlier.

Castlight isn’t the only health tech company ripe for an IPO. Practice Fusion and ZocDoc are both strong candidates to go public next, with total financing of $155 million and $99 million, respectively. The health IT market has recently received an immense amount of interest from investors, who poured a record $390 million into digital health companies in January, according to Rock Health.