According to the research, released on Friday, the proportion of ETF investors holding an ETF via their SMSF dropped from 45 per cent in April 2014 to 43 per cent in October 2014.
This is down from a high of 52 per cent in May 2011.
However, the number of SMSFs holding ETFs has continued to increase, up from 54,000 in April 2014 to 63,000 in October 2014.
There has been an overall growth of 52,000 since July 2008, the research showed.
“The key reasons for self-directed investors to use ETFs are diversification and access to overseas markets, highlighting the value investors see in utilising ETFs as an access vehicle,” said a statement from BetaShares.
Overall, the number of investors using ETFs has “surged dramatically”, according to the research.
Investor numbers have increased by 46 per cent in the 12 months to October 2014, up from 103,000 in the previous corresponding period, representing the fastest growth seen in the past four years.