Pacer ETFs has gathered $2 billion in assets under management in less than three years, gaining popularity from its rules-based, strategy-driven index exchange traded funds.

“We’re very excited to have crossed the $2 billion mark in under three years. Our rapid growth rate is due, in part, to our unique series of ETFs, the Pacer Trendpilot® Series, the Pacer Cash Cows IndexSM Series and the Pacer Custom ETF Series. Our goal is to offer investors timely solutions to help them maintain wealth and achieve higher returns over time,” Sean O’Hara, President of Pacer ETF Distributors, said in a note.

Specifically, Pacer Financial Inc. first started off in the ETF arena with a suite of so-called Pacer Trendpilot ETFs, including the Pacer Trendpilot US Large Cap ETF (BATS: PTLC), Pacer Trendpilot US Mid Cap ETF (BATS: PTMC) and Pacer Trendpilot 100 ETF (BATS: PTNQ), which have now gathered $909 million, $498 million and $206 million in assets under management, respectively.

The Pacer ETFs implement a type of trend following strategy that automatically adjusts exposures according to current market conditions. PTLC takes a 100% position in the S&P 500 Index when the benchmark is trading above its 200-day simple moving average for five consecutive days, moves to a 50% position to the large-cap index and 50% 3-month U.S. T-bills when the benchmark falls below its 200-day for five consecutive days, and takes on 100% 3-month US T-Bills if the benchmark closes lower than its value from five business days earlier. PTMC follows the same move between S&P MidCap 400 Index and US T-Bills, and PTNQ follows the similar trend following strategy with the Nasdaq-100 Index.

Related: Pacer Announces VETS: A Socially Conscious ETF

The providers includes a strategy that specifically targets companies with attractive free-cash-flow that could help limit drawdowns during market sell-offs and capture high returns during market bull runs. Investors interested in the free-cash-flow metric as a focused factor now have a number of options to choose from. For instance, the Pacer Global Cash Cows Dividend ETF (NYSEArca: GCOW), Pacer US Cash Cows 100 ETF (NYSEArca: COWZ)Pacer US Small Cap Cash Cows 100 ETF (BATS: CALF) and Pacer Developed Markets International Cash Cows 100 ETF (BATS: ICOW) all implement free-cash-flow yield screens to narrow down their universe.

Pacer also recently expanded upon its custom series line up with the recently launched Pacer Military Times Best Employers ETF (VETS), which invests in companies with the best hiring records for veterans.

For more information on ETFs, visit our ETF Performance Reports category.