My approach to the 'invest a lump sum immediately or spread it out' question.

I came into a $45,000 inheritance and spent three weeks agonizing about whether to invest it all at once or spread it over 6-12 months.

What the data says: lump sum investing outperforms dollar-cost averaging in about two-thirds of historical periods, because markets rise more often than they fall. If you invest $45,000 immediately and markets go up in the next year (which they do more often than not), you capture those gains on the full amount.

What happened in practice: I split the difference. I invested $25,000 immediately (in my existing allocation — VTI, VXUS, BND) and spread the remaining $20,000 over 5 months. I was honest with myself that I didn't have the stomach for full lump sum investing and that getting partially in immediately was better than waiting.

The outcome was fine. The market was up over the following year, so lump sum would have won slightly. But I didn't panic, I stayed invested, and the inheritance is now part of my long-term portfolio. That matters more than the theoretical optimum.