$1 million into $800,000, against $2.7 million for the index (after fund costs). Studies by the financial services market research company Dalbar say that the retention rate for bond and stock funds is three years. This means that in a 20-year period the investor changed funds seven times. Balanced funds are a bit better at four years, or five times. Some trading is necessary since not only is the investor return less than the best asset class, it is typically worse than the worst asset class, which would be better. Balanced funds may be better by reason of investor psychology. Financial advisors often agree that investors have poor timing, becoming less risk averse when markets are high and more risk averse when markets are low, a strategy that will actually result in less wealth in the long-term compared to someone who consistently invests over a long period regardless of market trends. This is consistent with recency bias and seems contrary to the acrophobia explanation. Similarly, Peter Lynch has stated that "Far more money has been lost by investors preparing for corrections or trying to anticipate corrections than has been lost in the corrections themselves." Proponents of the efficient-market hypothesis (EMH) claim that prices reflect all available information. EMH assumes that investors are highly intelligent and perfectly rational. However, others dispute this assumption. "Of course, we know stocks don't work that way". In particular, proponents of behavioral finance claim that investors are irrational but their biases are consistent and predictable. Viability of market timing Whether market timing is ever a viable investment strategy is controversial. Some may consider market timing to be a form of gambling based on pure chance, because they do not believe in undervalued or overvalued markets. The efficient-market hypothesis claims that financial prices always exhibit random walk behavior and thus cannot be predicted with consistency. Some consider market timing to be sensible in certain situations, such as an apparent bubble. However, because the economy is a complex system that contains many factors, even at times of significant market optimism or pessimism, it remains difficult, if not impossible, to predetermine the local maximum or minimum of future prices with any precision; a so-called bubble can last for many years before prices collapse. Likewise, a crash can persist for extended periods; stocks that appear to be "cheap" at a glance, can often become much cheaper afterwards, before then either