FACEBOOK'S FALL-FUMES

FACEBOOK Chief Executive Mark Zuckerberg's fortune took a more than $15 billion hit on Thursday, as the social media company suffered the biggest one-day wipe out in U.S. stock market history a day after executives forecast years of lower profit margins.

At least 16 brokerages cut their price targets on Facebook after Chief Financial Officer David Wehner startled an otherwise routine call with analysts saying the company faced a multi-year squeeze on the business margins.

That " bombshell " as one analyst termed it, played into the concerns on Wall Street that Facebook's model could be under threat after a year dominated by efforts to head off concerns over privacy and its role in global news flow.

Shares closed almost 19 percent at $176,26 wiping more than $120 billion off the company's value or nearly four times the entire market capitalization of Twitter.

Slowing revenue growth  initially pulled the stock down nearly 9 in after hours trading on Wednesday before losses picked up on the margin outlook.

"Over the next several years, we would anticipate that our operating margins will trend towards the  mid-30s  on a percentage basis," Wehner said on a conference call with analysts.

Facebook's margins fell to 44 percent in the second quarter from 47 percent a year ago as it spent heavily on security and initiatives to convince users the company was protecting their privacy.

The company also said  revenue growth from emerging markets  and the company's Instagram app, which has been less affected by privacy concerns, would not be enough to repair the damage.

The impact on the rest of the FAANG group of high-flying  tech stocks  was marginal.

Shares in Alphabet closed up 0.7 percent  while those in Apple fell 0.3 percent and Netflix closed barely higher. Amazon. com was up 2.3 percent following its own results after the bell on Thursday. [Agencies].