The PowerShares QQQ (NasdaqGS: QQQ), the sixth-largest U.S. ETF by assets will welcome back an old friend soon when Green Mountain Coffee Roasters (NasdaqGM: GMCR) rejoins the NASDAQ-100, QQQ’s underlying index, later this month.

Vermont-based Green Mountain, the maker of K-Cup and Vue single serve packs, will also join the NASDAQ-100 Equal Weighted Index (Nasdaq: NDXE) and the NASDAQ-100 Ex-Tech Sector Index (Nasdaq: NDXX) prior to market open on Thursday, August 22, 2013, according to a statement by NASDAQ OMX Global Indexes. Green Mountain is replacing biotech firm Life Technologies (NasdaqGM: LIFE).

At the close of U.S. markets Thursday, Green Mountain’s market value was $11.1 billion. Green Mountain was first added to the NASDAQ-100 in May 2011 only to be dropped from the index in December 2012. However, sometimes being dumped from the NASDAQ-100 is not all bad. Netflix (NasdaqGM: NFLX) was also dropped from the index at the same time as Green Mountain and both stocks have soared this year.

Assuming Green Mountain’s market cap stays around $11 billion, the stock would only account for a small percentage of QQQ upon reentering the ETF. As one example, semiconductor maker Altera (NasdaqGM: ALTR) has a market value of about $11 billion and has a weight of just 0.32% in QQQ. [Nasdaq 100 ETF Highest Since November 2000 After Streak]

By joining the NASDAQ-100 Equal Weighted Index, Green Mountain will be eligible for inclusion in the First Trust NASDAQ-100 Equal Weight Index Fund (NasdaqGS: QQEW) and the Direxion NASDAQ-100 Equal Weighted Index Shares (NYSEArca: QQQE). [Big Changes for QQQ]

PowerShares QQQ

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