Laith Khalaf: The slow fade of rational exuberance

We're nearly halfway through the year, and it's been a bit of a stinker for markets, especially in the US. The S&P 500 sits at around the 4,100 mark at the time of writing, down from 4,800 at the start of the year, a not inconsiderable 15% fall. That level of decline normally signals a good entry point into the market, but (whisper it sheepishly) this time might be different. The fall we have seen in the S&P 500 only wipes out gains seen in the previous six months, so if you had invested in US stocks a year ago, you're about evens. And if you invested 2 years ago, you're still in prof...