You are right holding bitcoins is really a good opportunity for getting profit. For sure when the halving occurs,
and you are holding a lot of bitcoins you are going to earn definitely earn a big profit.
No it's not sure that halving will give us profits. Take note that the price increase always started by manipulators so they will be the reason why the price will increase somewhere closer to halving. But because of expected happenings in the upcoming halving, people will think that will be the main reason so they will go with the flow and will start accumulating coins too resulting for a help in average of the price increase.