Will the exchange traded fund (ETF) industry be enjoying the April inflows and lead us to a flowering of markets in May?U.S.-listed ETFs and ETNs totaled approximately $540.2 billion at April 2009 month-end. This is a 10% increase up over March, when assets totaled approximately $489.2 billion, according to the National Stock Exchange.

April 2009 net cash inflows from all ETFs/ETNs totaled approximately $8.5 billion, with year-to-date net cash flows up 59% over the same time period one year ago. Also of interest: ETF/ETN notional trading volume totaled approximately $1.6 trillion for April 2009, representing 33% of all U.S. equity trading volume.

The recent changes and shifts in the ETF industry have worked to keep the industry relevant an interesting to both investors new to ETFs as well as the more seasoned ones. The latest wave of ETF innovation could be the key for the thriving industry.

As we’re starting to see some areas trending up and even crossing their long-term trend lines, May could wind up being an even better month for ETFs.

The opinions and forecasts expressed herein are solely those of Tom Lydon, and may not actually come to pass. Information on this site should not be used or construed as an offer to sell, a solicitation of an offer to buy, or a recommendation for any product.