Helped by Facebook (NasdaqGM: FB), LinkedIn (NYSE: LNKD) and other high-flying Internet and social media stocks, the Global X Social Media Index ETF (NasdaqGS: SOCL) has surged 45% this year.

SOCL investors are in for some more good news. After the close of U.S. markets Thursday, it was reported that social media darling Twitter has filed plans for an initial public offering. It was also reported that SOCL, the first ETF to focus on social media stocks, will add Twitter to its lineup.

SOCL was previously dubbed the “Facebook ETF” because the fund was the first ETF to add Facebook to its holdings. The ETF made room for Facebook a mere five days after the company’s May 2012 IPO and while that did not appear to be a great idea at the time, Facebook’s rebound has helped power SOCL higher this year and the stock is now the ETF’s largest holding at a weight of 12.2%, just ahead of the 12% allocated to Chinese Internet giant Tencent Holdings. [Facebook Surge Powers Social Media ETF]

Even before news of the Twitter IPO, SOCL had surged 11% since the start of August. In that time, the ETF hauled in $10.8 million of its $23.7 million in assets under management, according to Index Universe Data.

SOCL tracks the Solactive Social Media Index. No confirmation has been given as to when Twitter will join the index and ETF and at what percentage. [Internet ETFs a Rising Rates Sanctuary]

There was chatter on Twitter Thursday that although it is believed the company currently has less than $1 billion in revenue, the projected market value is between $10 billion and $20 billion, according to ABC News. At $15 billion, Twitter would be larger than SOCL top-10 holdings Groupon (NasdaqGM: GRPN) and Pandora (NYSE: P) combined. At $18 billion, Twitter would be more than triple the current size of Sina (NasdaqGM: SINA), the company referred to as the Twitter of China.

Global X Social Media Index ETF

ETF Trends editorial team contributed to this post. Tom Lydon’s clients own share of Facebook.