Financial startups may be hotter than ever in Silicon Valley, but public markets investors are decidedly more skeptical.

Just ask Renaud Laplanche, founder and CEO of online financial company Lending Club, the leader of this generation of fintech newcomers. In December 2014, Laplanche triumphantly presided over his company's blockbuster IPO, which valued Lending Club at more than $8 billion.

Thirteen months later, public life hasn't been pretty. Lending Club's stock spent last year slowly and consistently tumbling, cutting the company's current market cap to $3 billion as of this week, thanks in part to a broadly terrible beginning to 2016 for stock markets. On Thursday, shares closed at $8.02, down 47 percent from Lending Club's IPO price of $15.

Yet over that same period, the company's underlying growth has been unchecked: Revenue was up 104 percent year-over-year in the third quarter, when Lending Club also climbed out of the red, reporting a $1 million quarterly profit. (Fourth-quarter results will be reported in February.)

In a wide-ranging interview last week, Laplanche maintained he has "no regrets at all" about the IPO. And he mounted a spirited defense of the burgeoning online peer-to-peer--or "marketplace"--lending sector despite mounting criticisms, even throwing his support behind one of Lending Club's biggest rivals, Prosper.

"The stock price performance in the first year hasn't been good, but we didn't go public for a one-year period," Laplanche told me. "We went public to build a brand, show transparency, and make a statement about Lending Club being here to stay."

Lending Club's revenue growth also makes it the fastest-growing internet-based public company in America, Laplanche said, according to data compiled by Thomson Reuters and provided to Inc.

"I feel bad about investors. But if they're long-term investors and they're patient, I'm pretty sure that long-time company performance and the stock price will converge," Laplanche added.

Public markets are notoriously fickle, and Inc. has chronicled the many challenges they throw at entrepreneurs whose companies transition from private to public ownership. More troubling for Lending Club and its competitors, however, may be the mounting government scrutiny over their fast-growing and largely unregulated industry.

The marketplace lending sector, for which Lending Club is the largest and most prominent poster child, is facing increased attention from several government bodies, including the Treasury Department and the Consumer Financial Protection Bureau. Then, in December, the entire industry started hearing accusations of guilt by association in the San Bernardino shootings.

One of the shooters, Syed Rizwan Farook, took out a Prosper loan for $28,500 weeks before the suspected terrorist attacks, in which 14 people were killed. Federal officials have said that the Prosper loan may have helped Farook pay for ammunition and target practice. State and federal officials promptly took note.

"Just looking at what we know, it seems like the type of loan any bank would have made," Laplanche told me last week. "I don't know what else could have been done by Prosper or WebBank [which originates Prosper loans] or any other bank." 

Laplanche's comments were echoed last week by Prosper founder Chris Larsen, who left the company several years ago and is now running a digital payments-related startup, Ripple.

"Those companies have very good compliance groups," Larsen said in a separate interview, referring to both Lending Club and Prosper. "They have very closely regulated models already, and I don't see reckless behavior there."