The white paper gets into this, but beyond the "Average" return of LSI or DCA, downside risk must be analyzed. On one hand, if you DCA a windfall, your portfolio becomes dramatically more conservative than pre-windfall. However, LSI exposes you to very high nominal dollar risk and psychological worry. If a windfall brings you all the way to FI, do you by nature become more conservative? Logically, you're no longer in accumulation mode so I think you would.