There's a huge debate these days about whether the US stock market is in a bubble. So let me resolve the question by telling you that I've found a definite market bubble.
No, I'm not talking about the fact that US stocks are now officially in their longest bull market ever. Or that broad market indexes such as the S&P 500 and the Wilshire 5000 are at, or near, record levels.
No, I'm talking about one particular deal: PepsiCo paying an astounding US$3.2 billion ($4.7b) for a company that's in the bubble-making business.
The company, of course, is SodaStream, which has been flying high - or, if you prefer, bubbling up - because of the growing worldwide market for carbonated water:
I've been using SodaStream to make seltzer for years because changing carbon dioxide cartridges every once in a while is more convenient, less environmentally damaging and - above all - considerably cheaper than buying plastic bottles of seltzer and schlepping them home from the store.