Every generation of stock market investors is told the same reassuring lie: this time is different. Sometimes, for a while, it looks true.
New technologies really do change the world, and markets really do get more efficient at pricing genuine growth. But underneath every one of history’s great manias – the South Sea Bubble, 1929, the dot-com collapse of 2000, the credit bubble of 2007 – sits a recognisable anatomy. Cheap or easy leverage. A crowd convinced of one outcome. A handful of stocks carrying the index on their backs. And a valuation regime that has quietly detached itself from underlying earnings and economic output.