Hold points are technically called "stop loss" and should be planned prior to a devaluation, not during. They should be based on the price of your initial investment, where you project the bottom to be, where you see the recovery to be.

I highly recommend tiered investments into crypto. You would invest half of your funds at first when a crypto is steady, and set your stop loss at a reasonable point above and below that baseline. When a climb occurs, begin investing half of your remaining funds, set your stop losses, and invest the next half and so on.

When crypto drops, strategic stop losses will protect your investment or prevent more significant losses.