Timing investments is tough and the average investor is unfortunately not good at it. When mutual fund investors start allocating massively to a certain style, their ‘buy’ signal is often more of a ‘sell’ signal, since on average they move in at the wrong moment. The reverse is also true: when mutual fund investors start avoiding that style, this can be seen as a contrarian signal.
This collective bad timing explains most of the difference between investment returns and investor returns, sometimes referred to as the ‘behavior gap’. Investor returns take into account the timing effects and cash flows of investors. For example, when a large fund has a loss, or when a small fund has a gain, the difference between fund return and investor return can be considerable.
In a 2016 research paper1, Jason Hsu, Brett Myers and Ryan Whitby analyzed this interesting question using US mutual fund data, over the January 1991-June 2013 period. They found that the average mutual fund investor lagged a buy-and-hold strategy by 1.9%. This finding was persistent across different styles, varying from 1.3% for investors in value funds to 3.2% for investors in growth funds. Meanwhile, ‘passive’ investors, in market index funds, underperformed a buy-and-hold strategy by a whopping 2.7%.
What’s more, these results were all gross of fees and transaction costs. So, in practice, the gap between investor returns and fund performance is actually even larger. It is an established fact that the average mutual fund investor underperforms the index after costs, but the significant performance drag caused by poor timing is less well-known.
These findings are consistent with those reported by Ilia Dichev2, back in 2007, who showed that overall, US stock investors lag the buy-and-hold equity return by 1.3% (period 1926-2002, table 3 in the study). For international investors this figure is 1.5% (period 1973-2004, table 4). Figure 1 summarizes the findings from the literature.