Analysts at HSBC have suggested the popularity of balanced funds towards the end of 2012 was due to advisers attempting to maximise commission income before the implementation of new rules following the Retail Distribution Review (RDR).
Funds in the Investment Management Association's (IMA's) Mixed Investment categories - which house most balanced funds - were noticeably more popular just before the commission ban, the bank said.
Given balanced or multi-asset funds are, theoretically, less likely to underperform, the bank argued, clients were less likely to request a switch, allowing the adviser to keep commission for longer.
Under rules set out by the Financial Services Authority (FSA), commission was banned on retail investment products from 1 January.
However, advisers are in most cases allowed to retain the trail commissions on products arranged before 1 January, provided client assets are not "disturbed".
"Because IFAs can continue to receive trail commissions on assets written prior to 1 January, IFAs have been advising their clients to invest more money in balanced funds," the note read.
"If a client is invested in a balanced or multi-asset fund, he will have little reason to move out unless the fund underperforms.
"This is likely to result in lower churn and, hence, IFAs will be able to retain the trail commission coming out of these funds for a longer period."
"Post RDR, IFAs won't have the incentive to thrust money into these types of funds and, hence, we might see some impact on net sales."
The IMA's Mixed Investment (20-60% shares) sector, one of the renamed categories for balanced funds, was popular in 2012.
The sector took 22% of inflows on Cofunds - the UK's largest retail investment platform - in November, making it the best-selling sector for the second consecutive month.
"Mixed Investment (20-60% shares) seems to have created a boom with advisers in November," said Michelle Woodburn, head of fund group relations at Cofunds.
The Mixed Investment (40-85% shares), formerly the Balanced Managed sector, also proved popular.
It saw net retail sales of £134m in November, more than double its monthly average of £63m over the previous 12 months.
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