It may not be wise to invest all your money in Bitcoin at once. One strategy you could consider is Dollar Cost Averaging (DCA), which involves investing small amounts regularly, regardless of the price.
Exactly one should not put all amounts in just a single day because there are regular ups and downs in the worth so try to analyse the market and invest little by little according to the market shifting. It is also suggested that if you choose some good altcoins with Bitcoin then your profit will be extreme as these days some altcoins are trending.
Another better strategy is that whenever you have some payback in altcoins then sell these altcoins in order to invest in bitcoin but try to invest at the time when there is a decrease happening in the price of Bitcoin or altcoins and sell should be done when your money shows multiplication.