The most significant changes in Wall Street's sectors since 1999 will come into effect on Monday, Reuters reports. It will result in change of stocks volatility from one sector to another, while some investors will have to revise their portfolios.

Indices S&P Dow Jones perform reorganization of Global Industry Classification Standard (GICS).

It means that none of so-called FANG shares (Facebook, Amazon, Netflix, Alphabet /Google) will stay in information technology sector of S&P 500. Facebook and Alphabet will be included into telecommunication group, which will be renamed into communication services sector. Twitter, AT&T, Verizon Communications and CenturyLink will form this sector as well.

Apple Inc. will stay in technology sector and will account for 20% of IT index market capitalization.

Netflix will be moved into communication services sector from consumer discretionary sector where it was included before along with Amazon.com.

S&P will make changes after closing on Friday.

New changes reflect recent developments in such sectors as IT, media and consumer group.

Existing classification divides all companies into 11 sectors. The newest one, real estate sector, was separated from financial sector in 2016 and allowed investors to invest more effectively into real estate investments trusts (REIT).