From the world's most valuable brands, to a bitcoin diamond, this is The Week in Numbers. At $684 billion Amazon remains the world's most valuable brand. That's according to a new ranking by Kantar. Apple comes in second with an estimated value of $612 billion. But if U.S. brands still dominate, Chinese names are catching up fast. Social media giant Tencent makes the chart at number five, with retail titan Alibaba in seventh.Kantar Chief Marketing Officer Nathalie Burdet says top brands are soaring in value: "So first of all, an incredible growth - 42% and the total value of the top 100 equals $7.1 trillion. To put this into context, it's like the equivalent of the combined GDP of France and Germany."4,266 points was the record closing high for the S&P 500 stock index on Thursday. The U.S. index jumped after President Joe Biden embraced a bipartisan infrastructure deal in the Senate. That will see $1.2 trillion spent on roads, bridges and the like. Little wonder that construction gear maker Caterpillar was among the day's big gainers.About $3.6 billion is how much Panasonic got for its stake in Tesla. And the Japanese firm is probably feeling pretty pleased with itself, since it first acquired a piece of the automaker back in 2010, for just $30 million. Tesla shares have risen almost seven-fold just since March last year.Up to $67.2 billion is the valuation that Chinese ride-hailing giant Didi could get in its imminent New York IPO. That's based on calculations this week, after investors rushed to place orders for the shares on offer. The deal will mark the biggest U.S. share sale by a Chinese company since Alibaba raised $25 billion in 2014, and probably the biggest IPO in the U.S. this year. And 101.38 carats is the size of a diamond set to be auctioned at Sotheby's next month. The pear-shaped stone has an estimated value of up to $15 million. But it's not the size or value that marks a milestone, it's the payment terms. Sotheby's says it's the first time it will accept cryptocurrencies for a gem of such size.