I've heard that Bitcoin will finish mining in 2140, which is certainly a long way off. There's still a chance for us to continue dca BTC, as there's a strong possibility that in the future we'll see a higher BTC price than today, as BTC is constantly being mined, and we'll eventually see the BTC supply dwindle. Currently, I know there's only a small amount of unmined BTC left, approximately 1,100,000. While the number currently mined is 19,900,000, there's still time to accumulate BTC.
Okay I am not going to be concerned about how many bitcoins and been mined and unmined. We just need to understand that the factor of Dcaing on accumulating strategy won't get to restrictions because even while all the 21 millions has been mined, treaders and short term investors can still be supplying for those who want to buy and then there is going to be highily inflation on the purchase of bitcoin.
Quote
However, I'd like to know if there will be BTC miners once the supply is fully mined, and will the fees for sending from wallets to exchanges be high? I also wonder if the price fluctuations will be similar to the current bearish and bullish market. Currently, BTC is widely traded, buying at a low price and selling at a high price. But will BTC trading be possible in the future, similar to daily trading? I think this is worth discussing... 
After the total 21 millions of bitcoin is mined, there will be no space for mining and will not longer be earning on the mining tasks rather, they will still facilitate on integrating the complexities of the blockchain with also the efforts to validate transactions as usual and make assured the security system is solid enough for reliability.
Then they will be earning rewards from the above services with the high fee of transactions.