Which game would you rather play:

   A. Guaranteed $1,000 each month
   B. Every month, flip a coin. Heads gains $5,000, tails you lose $1,000.

Obviously B has greater expected return, but losing $1,000 hurts. What if you can't pay the rent that month?

To me, that's SPY vs. QQQ. Tech in general has higher expected return, but more volatility. If you can handle the volatility, then QQQ is better. If not, then not.

Ultimately, I'm taking a bet on tech because I believe tech has the greatest chance of improving the economy/world.

[I'm also not qualified, so do your own research]