Fidelity Investments has slashed its estimated valuation of Hadoop vendor Cloudera Inc. by 38 percent in response to concerns over high-value startups which have attracted a lot of private capital, but have delayed an IPO.

Fidelity, which has become one of the largest investors in pre-IPO companies through mutual funds that include the $100 billion-plus Contrafund, said it was concerned about a possible “startup bubble”. As a result its decided to mark down its assessment of privately owned Cloudera, Reuters reported.

The Register says that Cloudera’s drop in estimated value will be widely noted by Silicon Valley investors, who have been expected the company to announce an IPO for almost a year now.

The move comes following comments from Fidelity analyst Will Danoff last December that many of the astronomical valuations of Silicon Valley startups, particularly among the so-called $1 billion “unicorns”, are unrealistic. Danoff warned that we’d likely see a big bust among tech startups in the coming months.

At a time when companies like LinkedIn Corp., Twitter Inc. and Salesforce.com, Inc., have all seen their share price fall in recent days, Fidelity also marked down the value of its stake in file sharing firm Dropbox Inc., by twenty percent. Other companies, including Appirio Inc., CloudFlare Inc., Delphix Corp., and Nutanix Inc. also saw their valuations marked down.

Still, the Financial Times says that the falling valuations have done little to impact the capital flow to venture capital groups. Indeed, Dow Jones VentureSource’s preliminary data shows that venture capital firms have raised more money in the first quarter of 2016 since the days of the dotcom bubble.

Photo Credit: O’Reilly Conferences via Compfight cc