The 40k price level has been tested for several times, and the more often the price kisses or visits a support or resistance level, the weaker the level becomes, so I think we have right now another great opportunity to buy more Bitcoin, So, I have set some market orders way down to $38k should the price continues to dip down because $38k is another important level of support for the Bulls to fight, to try to push the price back up to continue the trend.
Actually I no that every investors has there own strategy that favours them but however I would suggest that you shouldn't only focus on buying Bitcoin when it gets to $38k because there is no any certainty that Bitcoin price will drop to that price you intend to buy because the reason why I'm saying this is that I have seen numerous of investors who focus on buying Bitcoin only when it gets to a particular price and they waited for a long time and the price could not get to there intended points as such they missed all the opportunity they had on taking advantage and accumulate Bitcoin.
So actually instead of waiting for the Bitcoin price to get to $38k before you start accumulating you could use the strategy @Jay was suggesting, from my understanding he suggested that while we wait for the price of Bitcoin to dip before we can Lum sum that there should be a plan to have another separate funds that will enable us keep accumulating using normal DCA while we wait for Bitcoin price to dip to your expected price before you could Lum sum, so perhaps I will advise you use this method so that it will enable you have some amount of Bitcoin if should incase the price doesn't get to your expected points.