I just read something pretty wild: A solo miner validated a block for just $75 worth of rented computing power and earned over $200,000 in Bitcoin. That's a 2,600-fold return on an investment smaller than a lunch.

The guy rented 1 petahash per second through CKPool and actually found block 938,092 – the full block reward of 3.125 BTC. Sounds like a lottery, but it's mathematically possible. Every attempt has the same probability, regardless of how much hash rate you have.

What surprises me: this is happening more and more often. Last year, 21 individual miners successfully found blocks and earned a total of 66 BTC. That's a 17 percent increase compared to the previous year. On-demand hash rate rental drastically lowers the barrier to entry – you no longer need expensive hardware, just a few dollars and luck.

The network difficulty has just risen to 144.4 trillion, but apparently this miner had the right timing. It's interesting to observe how the mining game is changing when anyone can theoretically give it a try.