Fifteen of XShares‘ line of HealthShares ETFs will close down, and their last trading day will be Sept. 19.

XShares President Jeff Feldman tells us it’s a simple matter of marketplace demand. “We were not generating assets in several of them, and they’re expensive to keep open.”

Closing the funds doesn’t mean that XShares didn’t believe in the products, but an acknowledgement that perhaps timing is everything. “We still believe our structure was right,” Feldman says, “and our timing was bad. So we decided to shutter some of them.”

When an ETF announces a closing, it follows an orderly process and investors are given plenty of notice before it actually takes place. Thirty-seven ETFs have closed this year, and we know that closing announcements tend to bring out the worriers: is the ETF industry in trouble? Are they a passing fad? But every industry has its successes and failures, and not every product to land in the marketplace can be a hit.

The entire line won’t close: four funds the marketplace seems to like will remain open. Meanwhile, Feldman says, they’ll revisit the old funds from time to time to see if they deserve another shot in the future.

The remaining funds will be:

• HealthShares Cancer (HHK)
  
• HealthShares European Drugs (HRJ)
  
• HealthShares Diagnostics (HHD)
• HealthShares Enabling Technologies (HHV)

HealthShares Enabling Technologies, however, is going to be renamed the Drug Discovery Tools Fund, and keep the same ticker symbol. A new fund will be joining the fold, as well: the HealthShares Asian Health, but it hasn’t begun trading.

Lower expense ratios for the remaining funds will be put in place, effective Oct. 1: for the cancer, diagnostic and drug discovery ETFs, the new expenses will be 0.60%, down from 0.75%. The European drugs will be 0.72%, down from 0.95%. The Asian health fund will be 0.95%. The four remaining funds will also get revamped benchmarks and number of constituents they’ll track, according to Murray Coleman for Index Universe.

The funds closing are:

• HealthShares Autoimmune-Inflammation (HHA)
• HealthShares Cardio Devices (HHE)
• HealthShares Cardiology (HRD)
• HealthShares Composite (HHQ)
• HealthShares Dermatology & Wound Care (HRW)
• HealthShares Emerging Cancer (HHJ)
• HealthShares European Medical Products & Devices (HHT)
• HealthShares GI/Gender Health (HHU)
• HealthShares Infectious Disease (HHG)
• HealthShares Metabolic-Endocrine Disorders (HHM)
• HealthShares Neuroscience (HHN)
• HealthShares Opthalmology (HHZ)
• HealthShares Orthopedic Repair (HHP)
• HealthShares Patient Care Services (HHB)
• HealthShares Respiratory/Pulmonary (HHR)