Bitcoin mining difficult has climbed to 1180923195.26 this weekend, a 30 percent increase from the previous difficulty. The increase came as more and more bitcoin miners come online to not only make money on transaction fees, but to earn the reward of discovering new bitcoins.
Up to 21 million bitcoins will ever exist, and the level of difficulty is contingent on the total amount of hashing power on the network. To prevent all of the 21 million bitcoins from being discovered too soon, the difficult increase makes calculations more challenging for miners.
This means that today’s most powerful miners are producing less bitcoins than they were earlier this week (as an example).
As such, manufacturers of bitcoin miners are in a close race to develop faster chips to keep up with the level of difficulty — often referred to as the space race of bitcoin mining.
So if you’re still mining with your computer’s graphics card, well, you’ll probably never see any profit.