The billionaire co-founders of Snapchat have lost 80% of their fortunes in the last 12 months after the social media company reported its slowest rate of quarterly sales growth ever. CEO Evan Spiegel – aka Mr Miranda Kerr – is now worth $2.3 billion… And while that’s not to be sneezed at, it’s a big drop on his $13.9 billion fortune this time last year. Co-founder Bobby Murphy also saw his wealth plunge to $1.9 billion this year. It’s all down to a drop in advertising dollars as tech companies fight over tight advertising budgets. Snapchat is one of several tech companies that have seen their share price plummet, and analysts are wondering how Facebook and Google are travelling. They release their financial updates this week.