Amid the frenzied fund-raising and soaring valuations for startups, Silicon Valley’s venture capital community is starting to get a little bummed out.

For the second straight quarter, the Silicon Valley Venture Capitalist Confidence Index fell, hitting its lowest point in two years. The index, measured by the University of San Francisco School of Management, has fallen four of the past five quarters.

The drop in confidence is notable because, by many other measures, one would expect VCs to be popping champagne corks and dancing the Macarena. Things like fundraising for VCs are at their highest point since 2007. And at times, Silicon Valley seems to be bursting at the seams.

So, why so blue?

Well, the report notes that VCs looking ahead are starting to worry about those hefty valuations, the growing costs of conducting their own business, the expanding types of venture investors who are increasing competition, and general macro economic issues like China’s economy and Greece’s economy that are looming over the world’s markets.

Speaking for the pessimists, Bob Ackerman of Allegis Capital told researchers:

“The unprecedented fund-raising and valuations associated with so-called ‘Unicorns’ and the knock-on effects for the venture ecosystem in terms of broader market expectations around valuations, compensation, and all aspects of the costs of doing business for venture companies gives reason for substantial pause,” he said in the report. “Expectations are beginning to outpace reality.”

Conducted for 46 consecutive quarters, the index surveys VCs about their outlook for the next six to 18 months. The results generate an index ranging from 1 to 5, with 1 being the worst and 5 being the best.

The index for the second quarter of 2015 fell to 3.73, down from 3.81. The latest figure also happens to be the same as the 11-year average.

Mark Cannice, professor of entrepreneurship and innovation at USF, conducts the research study each quarter.

In a statement about the latest report, Cannice said VCs expect overall conditions for IPOs and acquisitions to remain strong. But, he added, “Increasing concern about high valuations of venture-backed firms restrained sentiment.”