Sweeping changes are coming to several key sectors in the S&P 500 next year, with big names like Amazon and Netflix likely being moved into a new sector.

The changes don’t take effect until September, 2018, but already Wall Street is trying to figure out what big names will will be moved around, which will affect those who own different slices of the S&P 500 through Exchange Traded Funds (ETFs) and many mutual funds.

Late on Wednesday, the S&P Dow Jones Indices and MSCI jointly announced an overhaul of the Global Industry Classification system, which is how the industry divides the stock market into different sectors. The Telecomunications Services Sector will broaden out to include more internet and media stocks in a beefed-up new sector called Communication Services.

Many argue the move to expand and rebrand was long overdue.

Traders have often complained that the telecom space is far too small to even be given its own sector. Almost two decades ago, the sector encompassed 14 companies. But after several waves of consolidation, that number has dwindled to just three names – AT&T, Verizon and CenturyLink.

1) Telecom, consisting of telecom, Internet, and wireless services

2) Media & Entertainment, consisting of advertisers, broadcasters, cable/satellite providers, publishers, movie/entertainment

This makes sense, since many Telecom companies are in the Media & Entertainment business (AT&T owns Direct TV), and internet and wireless services are indeed communication services.

David Blitzer, Chairman of the S&P Dow Jones Index Committee, acknowledged that all these mediums are beginning to intersect: “The lines among media, communications, and content are blurred,” Blitzer said. “It is time to acknowledge this convergence and the overlapping services these companies provide. The Communication Services Sector addresses this progression.”

S&P won’t reveal the names until January, but based on the description a lot of companies are going to migrate from Consumer Discretionary to the new Communication Services sector.

1) Omnicom and Interpublic Group (advertising),

2) News Corp (publishing),

3) Charter, Comcast and Dish Network (cable & satellite),

4) Time Warner, 21st Century Fox, Viacom, and Disney (movies and entertainment), and

5) CBS, Discovery and Scripps Networks (broadcasting & cable TV).

This is a big list! S&P also says that the Internet and Direct Marketing Retail Sub-Industry and “select” companies in the Information Technology Sector, will also be moved into the Communication Services Sector.

This is huge, because it sounds like they want to put the big internet names like Amazon and Netflix, and potentially Google, into the new sector.

“The move corresponds with the changing way we communicate and access entertainment content and other information,” ETFtrends.com proprietor Tom Lydon told me. “This would in turn impact where investment money goes within the capital markets.”

What’s the end result? A big shift in sector weightings. Goldman Sachs, in a note in September, noted that the current composition of Technology, Consumer Discretionary and Telecommunications Sector would change drastically:

Information Technology:

Today: 24.5 percent

New weighting: 18 percent

Consumer Discretionary

Today: 11.9 percent

New weighting: 9 percent

Telecommunication Services

Today: 1.9 percent

New weighting as Communications Services: 10 percent

Source: Goldman Sachs

Under the new plan, technology would no longer make up a quarter of the overall S&P 500. With some big names likely migrating out, and with roughly $20 billion indexed to the largest Technology ETF (XLK) and $12 billion indexed to the largest Consumer Discretionary ETF (XLY), you can expect a lot of money to be moved around.