An Ohio Dunkin' made 6,000 donuts this week because a customer typed two extra zeros into an online order. Finance has a name for this exact mistake, and the donut version is the cheapest one ever recorded. They call it a fat finger error. Back in 2018, a Samsung Securities employee was paying a dividend of 1,000 won per share, about 94 cents, to roughly 2,000 employees. They typed "shares" instead of "won." The system approved it and deposited 2.8 billion ghost shares worth $105 billion into…