As for it being undiversified, NO investment by itself is completely diversified. Cash value life insurance can ADD diversity and security to a portfolio (the top companies have incredible financial strength, good policies can have a solid conservative return while meeting a life insurance need). Diversification is an issue with cash value life insurance if it makes up a good portion of your assets, and if it would, you shouldn’t be buying it.
Any reputable source will report mutual fund and stock returns as “annualized” figures, which takes the sequence of returns into account. Another term for this is “geometric average”, which again accounts for the order in which returns are received. So while there are some financial “experts” out there touting average returns (cough, Dave Ramsey), for the most part what you’re talking about here is not a factor.

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