Global tech stocks have lost about $1 trillion or 9 percent of market value this month, hurt by worries over slowing global demand, valuations and trade tensions between the United States and China.

A Refinitiv data analysis of 1,701 global technology firms — each with a market value of more than $100 million — showed that their combined market value was down to about $10.58 trillion on Oct. 23 from $11.64 trillion on Oct. 1.

However, the erosion in value pales in relation to the rapid run-up in these share prices over the past few years. Combined market capitalization of these stocks had doubled since 2013, leading the rise in major global stock indices.

In particular, combined capitalization of tech giants Facebook, Apple, Amazon, Netflix and Alphabet’s Google, popularly known as the FAANG stocks, had increased 3.5 times until this month's sell-off.

Compared to sell-offs earlier this year, this month's fall was bigger, indicating worsening sentiment about the sector, with investors bracing for further declines.

It has been one of the hardest hit by the tit-for-tat tariffs United States and China have imposed since March. Chinese tech firms have underperformed the broader stock market.

Tech shares were bolstered by strong earnings growth over the past few quarters, but recently analysts are turning more cautious due to slowing demand for tech products and the Washington-Beijing trade tensions.

Over the past month, analysts have cut their forward 12-month profit forecasts for tech firms by 3.06 percent, data from Refinitiv showed.

"We expect the trade war to intensify and demand in fourth quarter to slow down in sectors such as semiconductors, ODMs, Automation, memory, smartphones and servers," Macquarie said in a report this month.