The broad Nasdaq Composite Index, along with related exchange traded fund, is breaking out and could foreshadow similar breakouts in sideways trading among other key U.S. indices.

The Nasdaq Composite, along with the PowerShares QQQ (NasdaqGM: QQQ), which tracks the Nasdaq-100, experienced a bullish upward breakout last week from its sideways channel, a technical range between support and resistance prices. QQQ is up 6.1% over the past month.

The breakout from 10 weeks of sideways indecision suggests that the index is resuming its previous October 2014 advance, writes John Kosar, director of research at Asbury Research, for CNBC.

Moreover, Kosar points to the recent inflows into QQQ, which suggests that investors are supporting the push higher. QQQ has attracted $208.4 million in assets so far this month, according to data.

The Nasdaq Composite broke above its November 28 high of 4,811 last week, followed by a jump higher over the next day, which suggests investors are willing to jump in, defining the start of a new sustainable price trend.

The breakout in the Nasdaq may also augur additional upcoming breakouts from indices that have been stuck in sideways trading as well, including the S&P 500, Dow Jones Industrials, Dow transports, Russell 2000 and the PHLX Semiconductor Index, Kosar added.

Investors who would like to track potential bullish breakouts in these benchmark indices can utilize ETFs to track movements. For instance, the SPDR Dow Jones Industrial Average ETF (NYSEArca: DIA) follows the Dow Jones Industrial Average Index and the SPDR S&P 500 ETF (NYSEArca: SPY) has been a widely used option to capture the S&P 500. Over the past month, DIA rose 3.4% and SPY gained 4.2%. [Stick to U.S. Equity ETFs as Institutional Investors Remain Bullsih]