The proliferation of exchange-traded funds into seemingly every nook and cranny of the investment landscape has some people pondering whether the frontier is closed. Perhaps that’s premature, said speakers at an ETF industry gathering in New York City on Thursday sponsored by ETF Trends.

Matt Hougan, CEO of Inside ETFs, recalled that it was as long ago as early last decade when he read the first article saying that all of the ETF boxes have been checked and we’re at the end of ETFs.

Obviously, things haven’t played out that way.

“During the past three or four years there have been a lot of large ETF categories appear. Currency hedging and single-factor ETFs came out of nowhere and became huge things,” Hougan said, adding that various bond strategies could be included on that list.

“My guess is there will be more [new strategies],” he said. “I’m sort of long the creativity of the ETF industry. I think there’s still room to grow when you think about bottom-up hedge fund replication, private equity and other areas where there are still opportunities that can be delivered at low costs.”

And then there’s always the long talked about, yet slow to develop roll out of actively-managed ETFs. As noted by panel moderator Tom Lydon, the editor and publisher of ETF Trends, it has been tough to beat the market and to beat pure-beta, or index-based strategies during the long bull market. Investors have taken note and piled into passive funds as a result.

“But what happens when we have a significant bear market again?” he asked. “Will active management come back to life—albeit in different flavors? It’s probably going to happen because things operate in cycles.”

He posited that we could see active strategies within ETFs become more attractive, especially as more investors shift to ETFs and want to have multiple active strategies in their portfolios.

“We’ve already seen that to some degree with smart beta as we’ve gone from single-factor [strategies] with annual rebalancing to multi-factor with as often as monthly rebalancing,” Lydon said. “These really are active strategies.”

One of the factors behind the slow rollout of active ETFs has been fears that exposing active mutual fund portfolios to daily disclosure in an ETF needed for intraday trading runs the risk of front running by professional traders such as hedge funds.