It may not be 1999 all over again but the stock market certainly has that scary, bubbling feeling when it comes to the technology and e-commerce sector.
Until the last few weeks, internet stocks have had a gravity-defying run. Since then, the shares of some internet darlings such as Hong Kong-listed Tencent and Facebook in the US have been hit hard. Some new internet initial public offerings such as Japan Display in Tokyo and New York-listed King Digital Entertainment, the producer of the mega game hit Candy Crush, plunged on their first day of trading.
That has led some investors and market analysts to fret about an internet bubble about to burst. The upcoming listing of Alibaba had until recently been greeted with enthusiasm. Now many worry it may mark a market top. Its IPO will be preceded by high-profile Chinese e-commerce site JD.com and Sina Weibo, the messaging service giant.
There is no question that the valuations of many internet stocks, especially those in video gaming, social media and online retail, are well into frothy territory. The shares of Tencent more than doubled in the past 12 months. Less than two years ago, Facebook dipped below US$20. Today, its shares have more than tripled. Taking advantage of its lofty valuation, the social media giant has gone on a buying spree. Jaws dropped when it announced it was buying WhatsApp, the popular messaging company with modest sales, for a whopping US$19 billion. And Facebook's chief and co-founder Mark Zuckerberg said that was "a bargain"! Other large tech companies such as Google and Apple have been shopping as well.
Their buying spree has helped push up the price tags of many young companies with little or no earnings to lofty heights - another familiar tale from the dotcom bubble era.
Dozens of internet companies are preparing to list around the world to take advantage of the high valuations. But judging from the performance of recent listings, they may not prove to be a bonanza.
So, is it time to cash in? Well, for one thing, market crashes rarely happen where people expect them. The Nasdaq had three more years of an extraordinary bull run after former Fed chief Alan Greenspan warned against "irrational exuberance". The broader US market is still tethered to reality, despite a five-year bull run. The emerging and European markets are far from their pre-crisis highs.
It's those darling tech stocks we should worry about.