FYI: Like any business, even low-cost ETFs need to generate revenue to cover their costs.
Plenty of ETFs fail to garner the assets necessary to cover these costs and, consequently, ETF closures happen regularly. In fact, a significant percentage of ETFs are always at risk of closure. There’s no need to panic though: Broadly speaking, ETF investors don’t lose their investment when an ETF closes. A closure can, however, be inconvenient and costly.
The good news is that for each high-closure-risk ETF out there, there is almost always a larger, more viable product available to suit your investment needs.
Regards,
Ted
http://www.etf.com/sections/features-and-news/etf-education-managing-avoiding-closures