Superannuation laws before parliament could encourage funds to chase "asset bubbles" instead of being a stabilising influence on financial markets.
McKell Institute spokesman James Pawluk warns the legislative changes could also make it harder to deal with unpredictable "black swan" events as the bill is drafted for perfectly behaved markets.
"The proposed performance benchmarks will make it less viable for funds to adopt a strategy of steering clear of an asset bubble as it's forming, unless they are convinced it will burst or dissipate before the current performance period ends," Mr Pawluk told a parliamentary hearing on Thursday.
He said if funds don't chase the bubble and match their peers they could be named and shamed for poor performance and be cut off from members.
"The only rational strategy would be to pile in on the bubble, aiming to pull out just before it bursts or hug the index for good or bad," he said.
"These reforms will cause superannuation funds to behave more like retail investors, taking on their animal spirits, rather than acting as sophisticated long-term investors that provide a stabilising influence."
Justin Arter, chief executive of building and construction industry super fund Cbus, supported the objective of preventing multiple default accounts and making sure funds meet performance benchmarks.
He joined a growing coalition of think tanks, industry, professional, business groups and other funds who warn the legislation must not be passed in its current form.
Mr Arter warned "stapling" to be brought in under the bill may see workers tied to a fund when entering the workforce that does not provide insurance tailored to the risk of their present job or next job.
"In the case of many workers in hazardous occupations, it will leave many workers worse off," Mr Arter said.
CBus manages over $59 billion for 771,000 members and is a top-performing fund in Australia's $3 trillion pool of superannuation savings.
Maurice Blackburn Lawyers' personal injury specialist Kim Shaw gave evidence of the high rate of suicide in construction and said industry funds - unlike retail funds - made sure specific risk profiles were covered.
She was also concerned about workers being caught out by insurance policy exclusions when struck down by an injury or fatality.
The legislation would also put the onus on the trustee of the superannuation fund to show why any payment is justified, and face new penalties.
Ms Shaw described it as "an extraordinary intervention in the free market" by the Morrison government.
CPA Australia and Chartered Accountants Australia and New Zealand said this change was a narrowing of the current best interests duty that protects account holders.
Australian Institute of Superannuation Trustees spokesman David Haynes identified 14 areas where there were "holes" in the legislation and 10 big policy issues where witnesses giving evidence to the hearing said the Morrison government needed a rethink.
The committee must report back to parliament by April 22 and the draft bill is scheduled to take effect on July 1.
The legislation is yet to clear the lower house or the Senate.
Australian Associated Press