This really depends on how much money you have. It's a good general rule to keep a certain amount of money in cash or cash-like securities but there are limits

This really depends on how much money you have. It's a good general rule to keep a certain amount of money in cash or cash-like securities but there are limits to this. At a certain point, you lose out more on gains by keepin gmoney in cash than you'd lose by realizing losses to raise cash. If you believe in the long term future of your investments, the thing to avoid is a cash flow crunch. That's what cash on hand is for. Leveraged investments may face a margin call. That's fine if you believe in the assets and you can cover it. If you can't then you may be forced to sell low. Part of it too is psychological and being able to sleep at night. If you will suffer extraordinary stress by a 20% price correction then you're probably over-invested, just for your own wellbeing.