Bitcoin investment is too volatile for a person to monitor with an uncertain mindset, this could lead to the person selling their bitcoin at a time when the market value is low out of the fear of losing out and this can/will ultimately lead to them losing out when the price skyrockets.
When the price skyrockets isn't a time to take profits if your accumulation target and/or holding period has not been reached, remember Bitcoin is an investment for a long-term and targeting the bull run as a benchmark for success or harvesting is trading and not necessarily investment. I think they would lose out instead to get Bitcoin at a cheaper price. Even if the price skyrockets, there's still a chance to accumulate at the point they decide to get actionable, but the good prices are lost and they would get lesser quantities for same amounts compared to bigger quantities they would've got at the same price of they've started now to take action and embark on their accumulation journey.
Funny enough they may become redundant to take action when it's obvious to them that they failed in their gambling with Bitcoin price and may entirely miss out investing into Bitcoin. Waiting is detrimental, but being actionable in your Bitcoin involvement is the key to success in Bitcoin.
Exactly the reason why I said to increase the amount of funds invested into bitcoin on a weekly or monthly basis, a newbie deciding to make a bulk purchase of bitcoin is not something I would ever advice, they can though, IF they want to and IF there have the finance to back up that plan.
I also did not say to cash out on their investment when prices skyrocket, I said if they sold out on their investments during a DIP instead of HODL, they ultimately end up losing coz the price they sold at will be lower than their purchase price and when the price skyrockets, their loss is even more pronounced.
So they should buy at a steady rate (of the funds they invest and not the amount of bitcoin) over a period of time regardless of the increase in the market value, increasing the amount of funds they pour in over this period of time.