Before trading starts on Thursday, Twitter will be added to the S&P 500 stock index, a move for the social media platform that will grow the number of individual investors who own Twitter stock through index funds while tracking large-company stock gauge.

Twitters shares are still currently trading at 15% below where they were after the close of their first day of trading on Nov 7, 2013, while they are in line to replace the shady and controversial agriculture chemical maker Monsanto, who had been acquired by the German company Bayer, in a deal expected to close shortly.

This announcement came Monday night from S&P Dow Jones Indexes after the close of trading.

Twitters visibility in mainstream society has catapulted since U.S. President Donald Trump entered the White House, doing most of his announcements on this platform due to his inherent distrust of the mainstream media.  Trump has used this digital media platform to tweet messages on topics ranging from the economy and trade, to the NFL’s kneeling controversy at the beginning of the football season in 2017.

Twitter is up nearly 58% so far in 2018, and has more than doubled in just the past year, closing on Monday at $37.88, with an estimated market value of $28.5 billion heading into Tuesday’s trading day.  Now Twitters entry into the S&P sent its shares up more then 5% in early trading on Tuesday to its highest level ever since March 2015.

Why is Twitter’s shares going up so drastically due to this new development?  The reason is that this stocks inclusion into the S&P means mutual funds and ETFs, that copy and track the benchmark stock index must now buy Twitter shares to ensure they have the proper ballast in the stock.

The S&P 500 is an incredibly popular index, that many money manager’s performance is gauged against, and its viewed as the strongest benchmark of the overall performance of the stock market.  The Index is valued at over $7.8 trillion, with index funds assets making up around $2.2 trillion of this total, according to Dow Jones Indices.

Twitter will be added to the S&P’s broad “information technology” sector, a move that will boost the index’s already sizable exposure to tech stocks.  Tech stocks currently make up 26.2% of the highly valued index, which is up 20.8% from the beginning of 2018. This makes the indexes current tech exposure the highest its been since November 2000.  Twitters addition means investors will own an even larger piece of the technology market. Levels this high in the S&P haven’t been seen since the dot com bubble in 1999-2000.

Tech has been a major market leader in 2018 as the world becomes more and more of a digital based economy and investors are in turn investing their money in the part of the economy that is growing the most rapidly.  Taking all of this into account, its not surprising the tech sector of the S&P 500 recently reached new all time highs and will probably continue to climb moving forward.