David Shapiro explains the shock R35bn dive in Rupert company's valuation

South Africa's favourite market commentator gave us a glimpse of the insider's world in this week's episode of Rational Radio with Biznews.com's Alec Hogg. Most investors were bemused by today's R35bn slump in the market value of global luxury goods group Richemont, one of the major counters on the Johannesburg Stock Exchange (and hence in SA retirement portfolios). There was nothing untoward in the public domain, no official news announcement nor any other explanation for the price dive. But ever the sleuth, Shapiro's digging revealed that the sharp selloff was sparked by an investment analyst's report from Swiss bank UBS which took a dim view of Johann Rupert's group - sufficiently powerful to take 6% off the share price. Shapiro helps us understand this, and offers insights into Sasol, Naspers and Prosus in his always entertaining contribution.