the expert traders trade and earn and they do not wait for months , years etc, but they know when to trade, they do not wait for price go down or rise up, but they for their trade depend on the fluctuation of price occurring daily in bitcoin, so they earn money with the hourly or daily ups and downs in the price of bitcoin and never lose any amount of them and do not have to wait for longer.
I think nowadays the fluctuations are not more obvious and benefiting the traders have to wait for the price to increase till halving, or they have to go to the smaller exchanges where they can easily manipulate the price for buy and sell with their coins.
If a trader needs to wait for a halving to make money trading he is doing it all wrong. Traders need to trade off daily charts or weekley charts, not yearly charts.
More then just thinking positive, you need to be disciplined and stick to your guns. That's the #1 rule to trading.