eh is it? I thought it's end of Q2 tomorrow only. The $10 billion is probably the addition of Q1 and Q2 so far this fiscal year.

FTA: "Amazon’s founder has added $10.2 billion this year to his wealth and $7 billion since [Nov 8th]" - I'm going to interpret that as meaning that it's 10 billion over the course of a full year, which makes more sense than making losing 3 billion in December and making 10 billion in Q1/Q2 which would be necessary for your interpretation (of 10 billion in Q1/Q2) to make those numbers make sense.

Sorry I'm mistaken. The end of the fiscal year is the 5th of April in the UK.

In the US, I think this is different. So this is a more dramatic result considering.

The US fiscal year ends on September 30, but companies can set their own fiscal year. (Many C corps do end it at specific quarters)