How often should I review or rebalance my portfolio?

Rarely, on a schedule, not on the news. For most people once or twice a year is plenty: check that your split across equity, fixed income, and cash still matches your plan, top up or trim to bring it back, and otherwise leave it alone. Frequent tinkering usually lowers returns and raises stress. As a founder, the one thing worth watching a little more closely is your overall concentration: as your company equity grows in value, your true exposure to it grows too, which is a signal to keep steadily diversifying the liquid money, not to start fiddling with the core plan.