I wouldn't wait I would just buy and hold. Because why would I wait? We don't know if it's top or not. Even if it is top we will see higher in the future. So just dip in and buy whatever you can.
Hold as long as you don't need to withdraw and buy more as long as you have spare money to invest. There is no other option. Buy buy and buy more until you have decent amount. Then you can wait and enjoy higher prices with as much as Bitcoin you have in your hand.
When you are planning to invest in bitcoin, you shouldn’t just buy all at once and hold, it’s better you have a strategy when investing, and the best strategy is for you to make use of DCA strategy. Am not saying you should wait till bitcoin dumps before you start buying, but even if you will be buying now, then making use of DCA strategy is the best, and if you are planning to invest in bitcoin, then you should be ready to hold for a long period of time.
If you need maximum profit from your investment, then make sure you hold your bitcoin for a long period of time, some people are saying that bitcoin price is already high, but in next few years to come, the same set of people that didn’t invest now just because they think bitcoin price is too high will be the ones regretting why they didn’t invest now later in the future.